A Study to Assess the Safety, Tolerability, and Immunogenicity of RSVpreF in Adults at High Risk of Severe RSV Disease

A PHASE 3 PROTOCOL TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF RESPIRATORY SYNCYTIAL VIRUS (RSV) PREFUSION F SUBUNIT VACCINE IN ADULTS AT HIGH RISK OF SEVERE RSV DISEASE

Status

Completed

Phases

Phase 3

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT05842967

Acronym

MONET

Enrollment

885

Registered

2023-05-06

Start date

2023-05-11

Completion date

2024-03-18

Last updated

2025-08-08

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

RESPIRATORY SYNCYTIAL VIRUS (RSV)

Keywords

RESPIRATORY SYNCYTIAL VIRUS (RSV), ADULTS AT HIGH RISK, IMMUNOCOMPROMISED ADULTS

Brief summary

The purpose of this study is to learn about the safety and immunogenicity of a study vaccine (called RSVpreF) in several adult groups. Respiratory Syncytial Virus (RSV) is a common type of virus (germ) that can cause severe illness, where medical help is needed. RSV can lead to airway diseases in all ages. Vaccines help your body make antibodies which help fight against diseases. This is called an immune response. This study will measure how much antibody participants make after receiving RSVpreF (immunogenicity). The study consists of 2 groups (Substudy A and Substudy B). Substudy A is seeking approximately 675 participants who are: * Between 18 and 60 years of age. * Considered having a high likelihood of severe RSV disease due to certain long-term medical conditions. Such medical conditions do not include immunocompromising conditions. Participants will need to come to the study clinic at least 2 times. At the first clinic visit, participants will receive 1 shot of RSVpreF or placebo in the arm by chance. A placebo looks like the study vaccine but contains no active ingredients. At each clinic visit, a blood sample will be taken. A third (final) visit can be either completed in clinic or via telephone contact. This study is about 6 months long for each participant. Substudy B is seeking approximately 200 participants who are: * At least 18 years of age. About half of the participants will be at least 60 years of age. * Considered having a weakened immune system (immunocompromised). Participants will need to come to the study clinic at least 3 times. All participants will receive a shot of RSVpreF at the first study clinic visit. The second study clinic visit will be 1 month later. All participants will receive a second shot of the study vaccine at this second study clinic visit. Blood samples will be taken at the 3 study clinic visits. A fourth (final) visit can be either completed in clinic or via telephone contact. This study is about 7 months long for each participant.

Detailed description

This is a Phase 3 protocol that will assess the safety, tolerability, and immunogenicity of Pfizer's RSVpreF in adults at high risk of severe RSV disease. Each substudy design is detailed separately, and these substudies may be conducted in parallel, as required by the clinical plan, within the framework of this protocol. Substudy A Design: This is a Phase 3, multicenter, randomized, double-blinded, placebo-controlled study that will assess the safety, tolerability, and immunogenicity of Pfizer's RSVpreF in adults 18 to \<60 years of age considered to be at high risk of RSV disease due to certain chronic medical conditions. Approximately 675 participants ≥18 to \<60 years of age considered at high risk of RSV disease due to certain chronic medical conditions, excluding immunocompromising conditions, will be randomized to receive a single 120-µg dose of RSVpreF or placebo in a 2:1 ratio. Enrollment will be monitored to help ensure distribution of vaccination across the age range. The duration of study participation for each participant will be 6 months, with 3 scheduled visits. All participants will have blood drawn at baseline prior to vaccination and at 1 month after vaccination to assess immunogenicity. Immunogenicity elicited at 1 month after vaccination with RSVpreF in Substudy A will be bridged to the immunogenicity of participants 60 years of age and older in the C3671013 study, in which RSVpreF efficacy was demonstrated. Local reaction and systemic event data will be collected in an e-diary for 7 days after study vaccination (Days 1 through 7, where Day 1 is the day of vaccination). Reported Grade 3 reactogenicity will be assessed by the study site to determine if an unscheduled visit is required. For all participants, AEs will be collected from informed consent through 1 month following study intervention administration, and AESIs, NDCMCs and SAEs will be collected from informed consent throughout study participation. In addition, AEs occurring up to 48 hours after blood draws that are related to study procedures will be collected. Substudy B Design: This is a Phase 3, single-arm, open-label, multicenter study that will assess the safety, tolerability, and immunogenicity of Pfizer's RSVpreF in immunocompromised adults. Substudy B included approximately 200 immunocompromised adults ≥18 years of age, that will receive 2 120-µg doses of RSVpreF with an interval of 1 month. Approximately 100 participants will be ≥60 years of age and approximately 100 participants will be ≥18 to 60 years of age. Enrollment will be monitored to help ensure distribution of vaccination across the age ranges and underlying immunocompromising conditions. The duration of study participation for each participant will be 7 months, with 4 scheduled visits. All participants will have blood drawn at baseline prior to vaccination and at 1 month after (each) vaccination to assess immunogenicity. Local reaction and systemic event data will be collected in an e-diary for 7 days after study vaccination (Days 1 through 7, where Day 1 is the day of vaccination). Reported Grade 3 reactogenicity will be assessed by the study site to determine if an unscheduled visit is required. For all participants, AEs will be collected from informed consent through 1 month following the last study intervention administration, and AESIs, NDCMCs and SAEs will be collected from informed consent throughout study participation. In addition, AEs occurring up to 48 hours after blood draws that are related to study procedures will be collected.

Interventions

BIOLOGICALRSVpreF

120-µg

OTHERPlacebo

Placebo

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

PREVENTION

Masking

TRIPLE (Subject, Caregiver, Investigator)

Masking description

Substudy A is double blind therefore all parties (participant, site staff and sponsor) will be blinded to study intervention. Substudy B is open-label therefore no blinding requirements are in place since all participants will receive RSVpreF.

Intervention model description

Substudy A: Phase 3, multicenter, randomized, double-blinded, placebo-controlled study that will assess the safety, tolerability, and immunogenicity of Pfizer's RSVpreF in adults 18 to \<60 years of age considered to be at high risk of RSV disease due to certain chronic medical conditions. Approximately 675 participants ≥18 to \<60 years of age considered at high risk of RSV disease due to certain chronic medical conditions, excluding immunocompromising conditions, will be randomized to receive a single 120-µg dose of RSVpreF or placebo in a 2:1 ratio. Substudy B: Phase 3, single-arm, open-label, multicenter study that will assess the safety, tolerability, and immunogenicity of Pfizer's RSVpreF in immunocompromised adults. Approximately 200 immunocompromised adults ≥18 years of age will receive 2 120-µg doses of RSVpreF with an interval of 1 month. Approximately 100 participants will be ≥60 years of age and approximately 100 participants will be ≥18 to 60 years of age.

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

Substudy A Inclusion Criteria: 1. Capable of giving signed informed consent as described per protocol. 2. Participants ≥18 to \<60 years of age at study enrollment. 3. Life expectancy ≥12 months (365 days) in the opinion of the investigator at enrollment. 4. Participants who are willing and able to comply with all scheduled visits, vaccination plan, lifestyle considerations, and other study procedures. 5. Participants who are considered at high risk of RSV disease by virtue of the following: * Adults with chronic pulmonary (including asthma), cardiovascular (excluding isolated hypertension), renal, hepatic, neurologic, hematologic, or metabolic disorders (including diabetes mellitus). Chronic medical conditions for this substudy are defined as: \- Duration greater than 6 months. * Stable disease not requiring a significant change in therapy in the previous 6 weeks or hospitalization for worsening disease within 12 weeks before receipt of study intervention. * Requires regular medical follow-up or ongoing medication or hospitalization in the previous year. • Additional groups at high risk include: * Residents of nursing homes and other long-term care facilities. Substudy A

Exclusion criteria

1. Bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular injection. 2. History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s) or any related vaccine. 3. Participants who do not have adequate deltoid muscle mass to allow intramuscular vaccination, in the opinion of the investigator. 4. Serious chronic disorder, including metastatic malignancy, end-stage renal disease with or without dialysis, clinically unstable cardiac disease, or any other disorder that, in the investigator's opinion, excludes the participant from participating in the study. 5. Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination. 6. Other medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study. Note: Specific criteria for participants with known stable infection with HIV can be found in protocol. 7. Individuals who receive chronic systemic treatment with immunosuppressive therapy, including cytotoxic agents, immunosuppressive monoclonal antibodies, systemic corticosteroids\*, eg, for cancer or an autoimmune disease, or radiotherapy, from 60 days before study intervention administration or planned receipt throughout the study. \*Applies to systemic corticosteroids administered for ≥14 days at a dose of ≥20 mg/day of prednisone or equivalent (eg, for cancer or an autoimmune disease). Systemic corticosteroids administered at a dose of \<20 mg/day of prednisone or equivalent are permitted. Inhaled/nebulized, intra-articular, intrabursal, or topical (skin, eyes, or ears) corticosteroids are permitted. 8. Receipt of blood/plasma products or immunoglobulin within 60 days before study intervention administration or planned receipt of these medications prior to the final blood draw. Note: Monoclonal antibodies with targeted mechanisms of action used in the management of chronic illnesses (eg, migraine headaches, osteoporosis) are permitted, provided they do not meet exclusion criterion 7. 9. Previous vaccination with any licensed or investigational RSV vaccine or planned receipt during study participation. 10. Participation in other studies involving an investigational product within 28 days prior to consent and/or through and including the 6-month follow-up visit. 11. Investigator site staff directly involved in the conduct of the study and their family members, site staff otherwise supervised by the investigator, and sponsor and sponsor delegate employees directly involved in the conduct of the study and their family members. Substudy B Inclusion Criteria 1. Capable of giving signed informed consent as described per protocol. 2. Participants ≥18 years of age at study enrollment. 3. Life expectancy ≥12 months (365 days) in the opinion of the investigator at enrollment. 4. Participants who are willing and able to comply with all scheduled visits, vaccination plan, lifestyle considerations, and other study procedures. 5. Participants who are immunocompromised by virtue of the following: •Having known advanced NSCLC with at least 1 of the following: * Has received initial or maintenance chemotherapy at least 2 weeks (14 days) before enrollment (or is treatment-naïve), and is not expected to receive chemotherapy within at least 2 weeks (14 days) after dose administration of initial vaccination or second vaccination; and/or * Is receiving checkpoint inhibitor treatment (PD-1/PD-L1 inhibitor, CTLA-4 inhibitor) and has undergone at least 1 treatment cycle prior to enrollment; or * Is receiving targeted drug therapy (EGFR, ALK, ROS1, BRAF, RET, MET, NTRK inhibitors) and has undergone at least 1 treatment cycle prior to enrollment. OR - Is currently undergoing maintenance hemodialysis treatment secondary to end-stage renal disease . OR - Is on active immunomodulator therapy (eg, TNFα inhibitor, tofacitinib, or MTX) for an autoimmune inflammatory disorder (eg, inflammatory arthritis, such as rheumatoid arthritis, psoriatic arthritis, and juvenile idiopathic arthritis, or inflammatory bowel disease, such as ulcerative colitis or Crohn's disease) at a stable\*dose. \*Stable dose is defined as receiving the same dose for at least 3 months (84 days) with no changes in the 28 days prior to enrollment. See protocol for details on stable dose for MTX. OR - Is receiving an SOT (kidney, liver, lung, or heart) at least 3 months (84 days) prior to enrollment (Visit 201) and with no acute rejection episodes within 2 months (60 days) prior to enrollment (Visit 201). Substudy B

Design outcomes

Primary

Measure	Time frame	Description
SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 2	1 Month After Vaccination 2 (1-month post Vaccination 1)	GMT of RSV A and RSV B before vaccination were reported in this outcome measure. Assay results below the lower limit of quantification (LLOQ) were set to 0.5\*LLOQ. GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution).
SSB: Percentage of Participants With NDCMCs From Vaccination Throughout the Study	From Vaccination 1 (on Day 1) through 6 months after Vaccination 2 (1 month after Vaccination 1) [approximately up to maximum of 7 months]	A NDCMC was defined as a disease or medical condition that was not identified prior to study start and was expected to be persistent or otherwise long-lasting in its effects. Newly diagnosed chronic medical condition did not include illnesses considered to be temporary conditions.
SSB: Percentage of Participants With SAEs Throughout the Study	From Vaccination 1 (on Day 1) through 6 months after Vaccination 2 (1 month after Vaccination 1) [approximately up to maximum of 7 months]	An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention. An SAE was defined as any untoward medical occurrence that, at any dose, met one or more of the following criteria - resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect and was a suspected transmission via a Pfizer product of an infectious agent, pathogenic or non-pathogenic and other important medical event were included in this outcome measure.
SSB: GMT of NT for RSV A and RSV B Before Vaccination 1	Before Vaccination 1 (on Day 1)	GMT of RSV A and RSV B before vaccination were reported in this outcome measure. Assay results below the lower limit of quantification (LLOQ) were set to 0.5\*LLOQ. GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution).
SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 1	1 Month After Vaccination 1 (on Day 1)	GMT of RSV A and RSV B before vaccination were reported in this outcome measure. Assay results below the lower limit of quantification (LLOQ) were set to 0.5\*LLOQ. GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution).
SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Within 7 Days after Vaccination (Vaccination on Day 1)	Local reactions included pain at injection site, redness and swelling, recorded by participants in an electronic diary (e-diary). Pain at injection site was graded as mild: did not interfere with activity; moderate: interfered with activity and severe: prevented daily activity. Redness and swelling were measured and recorded in measuring device units, where 1 measuring device unit =0.5 centimeter (cm). Redness and swelling were graded as mild: \>2.5 cm to 5.0 cm; moderate: \>5.0 cm to 10.0 cm; severe: \>10 cm.
SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Within 7 Days after Vaccination (Vaccination on Day 1)	Systemic events included fever, fatigue, headache, vomiting, nausea, diarrhea, muscle pain and joint pain. These were recorded by participants in an e-diary. Fever defined as oral temperature \>=38.0 degrees Celsius (deg C) and categorized as mild: \>=38.0 to 38.4 deg C, moderate: \>38.4 to 38.9 deg C and severe: \>38.9 to 40.0 deg C. Vomiting categorized as mild: 1-2 times in 24 hours (h); moderate: \>2 times in 24h; severe: required intravenous (IV) hydration. Diarrhea categorized as mild: 2-3 loose stools in 24h; moderate: 4-5 loose stools in 24h; severe: 6 or more loose stools in 24h. Headache, fatigue, nausea, muscle pain and joint pain were categorized as mild: didn't interfere with activity; moderate: some interference with activity; severe: prevented daily routine activity.
SSA: Percentage of Participants With Adverse Events (AEs) From Vaccination Through 1 Month After Vaccination	Within 1 Month after Vaccination (Vaccination on Day 1)	An AE was defined as any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention. Only AEs collected by non-systematic assessment (i.e. excluding local reactions and systemic events) were included. AEs included both serious and all non-serious adverse events.
SSA: Percentage of Participants With Newly Diagnosed Chronic Medical Conditions (NDCMCs) From Vaccination Throughout the Study	Within 6 Months after Vaccination (Vaccination on Day 1)	A NDCMC was defined as a disease or medical condition that was not identified prior to study start and was expected to be persistent or otherwise long-lasting in its effects. Newly diagnosed chronic medical condition did not include illnesses considered to be temporary conditions.
SSA: Percentage of Participants With Serious Adverse Events (SAEs) Throughout the Study	Within 6 Months after Vaccination (Vaccination on Day 1)	An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention. An SAE was defined as any untoward medical occurrence that, at any dose, met one or more of the following criteria - resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect and was a suspected transmission via a Pfizer product of an infectious agent, pathogenic or non-pathogenic and other important medical event were included in this outcome measure.
SSA: Geometric Mean Ratio (GMR) Estimated by Ratio of the Geometric Mean Titers (GMTs) at 1 Month After Vaccination in Study C3671023 Participants Compared to Study C3671013 Adults >= 60 Years	At 1 Month after Vaccination (Vaccination on Day 1)	In this outcome measure, GMTs for RSV A and RSV B neutralizing titers (NTs) are reported. In statistical section, GMT ratio estimated by the ratio of the GMTs for RSV A and RSV B serum NTs at 1 month after vaccination with RSVpreF in current study C3671023 participants to that in study C3671013 adults \>=60 years of age, is reported. GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student t distribution).
SSA: Percentage of Participants With Seroresponse Rate and Difference in Seroresponse Rates of RSV A and RSV B Serum NTs at 1 Month After Vaccination for Participants in Study C3671023 and C3671013 Adults >= 60 Years	At 1 Month after Vaccination (Vaccination on Day 1)	Seroresponse was defined as achieving a \>=4-fold rise from baseline (before vaccination), if the baseline measurement was above the lower limit of quantitation (LLOQ). If the baseline measurement was below the LLOQ, a postvaccination assay result \>=4\* LLOQ was considered a seroresponse.
SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Within 7 Days after Vaccination 1 (Vaccination 1 on Day 1)	Local reactions included pain at injection site, redness and swelling, recorded by participants in an e-diary. Pain at injection site was graded as mild: did not interfere with activity; moderate: interfered with activity and severe: prevented daily activity. Redness and swelling were measured and recorded in measuring device units, where 1 measuring device unit=0.5 cm. Redness and swelling were graded as mild: \> 2.0 cm to 5.0 cm; moderate: \> 5.0 cm to 10.0 cm and severe: \> 10 cm.
SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Within 7 Days after Vaccination 2 (Vaccination 2: 1-month post-vaccination 1 on Day 1)	Local reactions included pain at injection site, redness and swelling, recorded by participants in an e-diary. Pain at injection site was graded as mild: did not interfere with activity; moderate: interfered with activity and severe: prevented daily activity. Redness and swelling were measured and recorded in measuring device units, where 1 measuring device unit = 0.5 cm. Redness and swelling were graded as mild: \>2.0 cm to 5.0 cm; moderate: \>5.0 cm to 10.0 cm and severe: \>10 cm.
SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Within 7 Days after Vaccination 1 (Vaccination 1 on Day 1)	Systemic events included fever, fatigue, headache, vomiting, nausea, diarrhea, muscle pain and joint pain. These were recorded by participants in an e-diary. Fever defined as oral temperature \>=38.0 degrees Celsius (deg C) and categorized as mild: \>=38.0 to 38.4 deg C, moderate: \>38.4 to 38.9 deg C and severe: \>38.9 to 40.0 deg C. Vomiting categorized as mild: 1-2 times in 24 hours (h); moderate: \>2 times in 24h; severe: required intravenous (IV) hydration. Diarrhea categorized as mild: 2-3 loose stools in 24h; moderate: 4-5 loose stools in 24h; severe: 6 or more loose stools in 24h. Headache, fatigue, nausea, muscle pain and joint pain were categorized as mild: didn't interfere with activity; moderate: some interference with activity; severe: prevented daily routine activity.
SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Within 7 Days after Vaccination 2 (Vaccination 2: 1-month post-vaccination 1 on Day 1)	Systemic events included fever, fatigue, headache, vomiting, nausea, diarrhea, muscle pain and joint pain. These were recorded by participants in an e-diary. Fever defined as oral temperature \>=38.0 degrees Celsius (deg C) and categorized as mild: \>=38.0 to 38.4 deg C, moderate: \>38.4 to 38.9 deg C and severe: \>38.9 to 40.0 deg C. Vomiting categorized as mild: 1-2 times in 24 hours (h); moderate: \>2 times in 24h; severe: required intravenous (IV) hydration. Diarrhea categorized as mild: 2-3 loose stools in 24h; moderate: 4-5 loose stools in 24h; severe: 6 or more loose stools in 24h. Headache, fatigue, nausea, muscle pain and joint pain were categorized as mild: didn't interfere with activity; moderate: some interference with activity; severe: prevented daily routine activity.
SSB: Percentage of Participants With AEs From Vaccination 1 Through 1 Month After Vaccination 2	From Vaccination 1 (on Day 1) through 1 month after Vaccination 2 (1 month after Vaccination 1) [approximately up to maximum of 2 months]	An AE was defined as any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention. Only AEs collected by non-systematic assessment (i.e. excluding local reactions and systemic events) were included. AEs included both serious and all non-serious adverse events.

Secondary

Measure	Time frame	Description
SSB: GMFR of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 2	At 1 Month After Vaccination 1 (on Day 1) to 1 Month Post-Vaccination 2	GMFRs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution).
SSA: GMT of NTs for RSV A and RSV B Before Vaccination and 1 Month After Vaccination	SSA: Before Vaccination (on Day 1) and 1 Month After Vaccination	GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution).
SSA: GMFR of NTs for RSV A and RSV B From Before Vaccination to 1 Month After Vaccination	SSA: Before Vaccination (on Day 1) and 1 Month After Vaccination	GMFRs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution).
SSB: Geometric Mean Fold Rise (GMFR) of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 1	At 1 Month After Vaccination 1 (on Day 1) to 1 Month Post-Vaccination 1	GMFRs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution).

Countries

United States

Participant flow

Recruitment details

Substudy A (SSA) and substudy B (SSB) are reported differently. SSA was randomized; SSB was open-label single-arm. Enrollment number 885 derived from participants with IP assigned in SSA (681 randomized) and SSB (204). Since no randomization in SSB (single arm), tables of SSB present 217 participants as starting substudy (signed informed consent), out of which 203 vaccinated. In SSA: 678 vaccinated.

Pre-assignment details

For immunogenicity analysis for SSA, as planned, data of participants \>=60 years vaccinated with RSVpreF in C3671013 \[NCT05035212\] study is used for comparison. These participants were not enrolled in the present study C3671023 \[NCT05842967\], only the relevant historical data was used for comparison as per the objectives.

Participants by arm

Arm	Count
SSA: RSVpreF Participants aged \>=18 to \<60 years received RSVpreF 120 mcg intramuscularly on Day 1 of SSA.	453
SSA: Placebo Participants aged \>=18 to \<60 years received placebo (lyophile matched to RSVpreF) intramuscularly on Day 1 of SSA.	225
SSB: RSVpreF, >= 18 to < 60 Years Participants aged \>=18 to \<60 years received RSVpreF 120 mcg intramuscularly first dose on Day 1 of SSB (Vaccination 1) and second dose on 1-month post-vaccination 1 (Vaccination 2).	96
SSB: RSVpreF, >= 60 Years Participants aged \>=60 years received RSVpreF 120 mcg intramuscularly first dose on Day 1 of SSB (Vaccination 1) and second dose on 1-month post-vaccination 1 (Vaccination 2).	107
Total	881

Withdrawals & dropouts

Period	Reason	FG000	FG001	FG002	FG003
Period 1: SSA	Adverse Event	1	1	0	0
Period 1: SSA	Death	1	0	0	0
Period 1: SSA	Lost to Follow-up	16	4	0	0
Period 1: SSA	Physician Decision	1	0	0	0
Period 1: SSA	Randomized but not vaccinated	1	2	0	0
Period 1: SSA	Withdrawal by Subject	2	2	0	0
Period 2: SSB	Adverse Event	0	0	2	0
Period 2: SSB	Enrolled but not vaccinated	0	0	5	9
Period 2: SSB	Lost to Follow-up	0	0	4	3
Period 2: SSB	Protocol Violation	0	0	0	1
Period 2: SSB	Withdrawal by Subject	0	0	1	0

Baseline characteristics

Characteristic	SSB: RSVpreF, >= 60 Years	Total	SSB: RSVpreF, >= 18 to < 60 Years	SSA: RSVpreF	SSA: Placebo
Age, Customized 18 to <60 years	0 Participants	774 Participants	96 Participants	453 Participants	225 Participants
Age, Customized >=60 years	107 Participants	107 Participants	0 Participants	0 Participants	0 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	3 Participants	161 Participants	8 Participants	102 Participants	48 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	101 Participants	712 Participants	88 Participants	348 Participants	175 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	3 Participants	8 Participants	0 Participants	3 Participants	2 Participants
Race (NIH/OMB) American Indian or Alaska Native	3 Participants	5 Participants	1 Participants	1 Participants	0 Participants
Race (NIH/OMB) Asian	2 Participants	41 Participants	6 Participants	24 Participants	9 Participants
Race (NIH/OMB) Black or African American	15 Participants	203 Participants	25 Participants	106 Participants	57 Participants
Race (NIH/OMB) More than one race	0 Participants	4 Participants	0 Participants	3 Participants	1 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants	4 Participants	1 Participants	2 Participants	1 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants	10 Participants	0 Participants	5 Participants	5 Participants
Race (NIH/OMB) White	87 Participants	614 Participants	63 Participants	312 Participants	152 Participants
Sex: Female, Male Female	53 Participants	521 Participants	56 Participants	260 Participants	152 Participants
Sex: Female, Male Male	54 Participants	360 Participants	40 Participants	193 Participants	73 Participants

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk	EG002 affected / at risk	EG003 affected / at risk
deaths Total, all-cause mortality	1 / 453	0 / 225	0 / 96	0 / 107
other Total, other adverse events	301 / 453	135 / 225	73 / 96	92 / 107
serious Total, serious adverse events	5 / 453	7 / 225	7 / 96	15 / 107

Outcome results

Primary

SSA: Geometric Mean Ratio (GMR) Estimated by Ratio of the Geometric Mean Titers (GMTs) at 1 Month After Vaccination in Study C3671023 Participants Compared to Study C3671013 Adults >= 60 Years

In this outcome measure, GMTs for RSV A and RSV B neutralizing titers (NTs) are reported. In statistical section, GMT ratio estimated by the ratio of the GMTs for RSV A and RSV B serum NTs at 1 month after vaccination with RSVpreF in current study C3671023 participants to that in study C3671013 adults \>=60 years of age, is reported. GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student t distribution).

Time frame: At 1 Month after Vaccination (Vaccination on Day 1)

Population: C3671023: Evaluable immunogenicity population: participants eligible for SSA; received study interventions (RSVpreF or placebo) to which they were randomized; had 1-month postvaccination blood collection 27-42 days after vaccination; had at least 1 valid and determinate assay result 1 month after vaccination; had no major protocol violations from vaccination up to 1-month postvaccination blood draw. C3671013: Immunogenicity subset. Number Analyzed = participants evaluable for specified rows.

Arm	Measure	Group	Value (LEAST_SQUARES_MEAN)
SSA: RSVpreF	SSA: Geometric Mean Ratio (GMR) Estimated by Ratio of the Geometric Mean Titers (GMTs) at 1 Month After Vaccination in Study C3671023 Participants Compared to Study C3671013 Adults >= 60 Years	RSV A	41097 Titer
SSA: RSVpreF	SSA: Geometric Mean Ratio (GMR) Estimated by Ratio of the Geometric Mean Titers (GMTs) at 1 Month After Vaccination in Study C3671023 Participants Compared to Study C3671013 Adults >= 60 Years	RSV B	37416 Titer
SSA: Placebo	SSA: Geometric Mean Ratio (GMR) Estimated by Ratio of the Geometric Mean Titers (GMTs) at 1 Month After Vaccination in Study C3671023 Participants Compared to Study C3671013 Adults >= 60 Years	RSV A	26225 Titer
SSA: Placebo	SSA: Geometric Mean Ratio (GMR) Estimated by Ratio of the Geometric Mean Titers (GMTs) at 1 Month After Vaccination in Study C3671023 Participants Compared to Study C3671013 Adults >= 60 Years	RSV B	24680 Titer

95% CI: [1.396, 1.759]

95% CI: [1.333, 1.725]

Primary

SSA: Percentage of Participants With Adverse Events (AEs) From Vaccination Through 1 Month After Vaccination

An AE was defined as any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention. Only AEs collected by non-systematic assessment (i.e. excluding local reactions and systemic events) were included. AEs included both serious and all non-serious adverse events.

Time frame: Within 1 Month after Vaccination (Vaccination on Day 1)

Population: Safety population included all enrolled participants who received the study intervention.

Arm	Measure	Value (NUMBER)
SSA: RSVpreF	SSA: Percentage of Participants With Adverse Events (AEs) From Vaccination Through 1 Month After Vaccination	7.1 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Adverse Events (AEs) From Vaccination Through 1 Month After Vaccination	7.6 Percentage of participants

Primary

SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination

Local reactions included pain at injection site, redness and swelling, recorded by participants in an electronic diary (e-diary). Pain at injection site was graded as mild: did not interfere with activity; moderate: interfered with activity and severe: prevented daily activity. Redness and swelling were measured and recorded in measuring device units, where 1 measuring device unit =0.5 centimeter (cm). Redness and swelling were graded as mild: \>2.5 cm to 5.0 cm; moderate: \>5.0 cm to 10.0 cm; severe: \>10 cm.

Time frame: Within 7 Days after Vaccination (Vaccination on Day 1)

Population: E-diary safety population included all participants who received the study intervention with at least 1 day of e-diary data transmitted.

Arm	Measure	Group	Value (NUMBER)
SSA: RSVpreF	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Pain at injection site: Mild	29.7 Percentage of Participants
SSA: RSVpreF	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Pain at injection site: Moderate	5.5 Percentage of Participants
SSA: RSVpreF	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Pain at injection site: Severe	0 Percentage of Participants
SSA: RSVpreF	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Redness: Mild	3.8 Percentage of Participants
SSA: RSVpreF	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Redness: Moderate	2.2 Percentage of Participants
SSA: RSVpreF	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Redness: Severe	0 Percentage of Participants
SSA: RSVpreF	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Swelling: Mild	4.0 Percentage of Participants
SSA: RSVpreF	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Swelling: Moderate	2.9 Percentage of Participants
SSA: RSVpreF	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Swelling: Severe	0.2 Percentage of Participants
SSA: Placebo	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Redness: Mild	0 Percentage of Participants
SSA: Placebo	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Redness: Severe	0 Percentage of Participants
SSA: Placebo	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Swelling: Severe	0 Percentage of Participants
SSA: Placebo	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Pain at injection site: Mild	10.2 Percentage of Participants
SSA: Placebo	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Swelling: Moderate	0.4 Percentage of Participants
SSA: Placebo	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Pain at injection site: Moderate	0.4 Percentage of Participants
SSA: Placebo	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Redness: Moderate	0.4 Percentage of Participants
SSA: Placebo	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Pain at injection site: Severe	0 Percentage of Participants
SSA: Placebo	SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination	Swelling: Mild	0.4 Percentage of Participants

Primary

SSA: Percentage of Participants With Newly Diagnosed Chronic Medical Conditions (NDCMCs) From Vaccination Throughout the Study

A NDCMC was defined as a disease or medical condition that was not identified prior to study start and was expected to be persistent or otherwise long-lasting in its effects. Newly diagnosed chronic medical condition did not include illnesses considered to be temporary conditions.

Time frame: Within 6 Months after Vaccination (Vaccination on Day 1)

Population: Safety population included all enrolled participants who received the study intervention.

Arm	Measure	Value (NUMBER)
SSA: RSVpreF	SSA: Percentage of Participants With Newly Diagnosed Chronic Medical Conditions (NDCMCs) From Vaccination Throughout the Study	0.7 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Newly Diagnosed Chronic Medical Conditions (NDCMCs) From Vaccination Throughout the Study	2.2 Percentage of participants

Primary

SSA: Percentage of Participants With Serious Adverse Events (SAEs) Throughout the Study

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention. An SAE was defined as any untoward medical occurrence that, at any dose, met one or more of the following criteria - resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect and was a suspected transmission via a Pfizer product of an infectious agent, pathogenic or non-pathogenic and other important medical event were included in this outcome measure.

Time frame: Within 6 Months after Vaccination (Vaccination on Day 1)

Population: Safety population included all enrolled participants who received the study intervention.

Arm	Measure	Value (NUMBER)
SSA: RSVpreF	SSA: Percentage of Participants With Serious Adverse Events (SAEs) Throughout the Study	1.1 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Serious Adverse Events (SAEs) Throughout the Study	3.1 Percentage of participants

Primary

SSA: Percentage of Participants With Seroresponse Rate and Difference in Seroresponse Rates of RSV A and RSV B Serum NTs at 1 Month After Vaccination for Participants in Study C3671023 and C3671013 Adults >= 60 Years

Seroresponse was defined as achieving a \>=4-fold rise from baseline (before vaccination), if the baseline measurement was above the lower limit of quantitation (LLOQ). If the baseline measurement was below the LLOQ, a postvaccination assay result \>=4\* LLOQ was considered a seroresponse.

Time frame: At 1 Month after Vaccination (Vaccination on Day 1)

Arm	Measure	Group	Value (NUMBER)
SSA: RSVpreF	SSA: Percentage of Participants With Seroresponse Rate and Difference in Seroresponse Rates of RSV A and RSV B Serum NTs at 1 Month After Vaccination for Participants in Study C3671023 and C3671013 Adults >= 60 Years	RSV A	93.1 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Seroresponse Rate and Difference in Seroresponse Rates of RSV A and RSV B Serum NTs at 1 Month After Vaccination for Participants in Study C3671023 and C3671013 Adults >= 60 Years	RSV B	93.4 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Seroresponse Rate and Difference in Seroresponse Rates of RSV A and RSV B Serum NTs at 1 Month After Vaccination for Participants in Study C3671023 and C3671013 Adults >= 60 Years	RSV A	88.0 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Seroresponse Rate and Difference in Seroresponse Rates of RSV A and RSV B Serum NTs at 1 Month After Vaccination for Participants in Study C3671023 and C3671013 Adults >= 60 Years	RSV B	85.0 Percentage of participants

95% CI: [1.2, 9.2]

95% CI: [4.2, 12.6]

Primary

SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination

Systemic events included fever, fatigue, headache, vomiting, nausea, diarrhea, muscle pain and joint pain. These were recorded by participants in an e-diary. Fever defined as oral temperature \>=38.0 degrees Celsius (deg C) and categorized as mild: \>=38.0 to 38.4 deg C, moderate: \>38.4 to 38.9 deg C and severe: \>38.9 to 40.0 deg C. Vomiting categorized as mild: 1-2 times in 24 hours (h); moderate: \>2 times in 24h; severe: required intravenous (IV) hydration. Diarrhea categorized as mild: 2-3 loose stools in 24h; moderate: 4-5 loose stools in 24h; severe: 6 or more loose stools in 24h. Headache, fatigue, nausea, muscle pain and joint pain were categorized as mild: didn't interfere with activity; moderate: some interference with activity; severe: prevented daily routine activity.

Time frame: Within 7 Days after Vaccination (Vaccination on Day 1)

Population: E-diary safety population included all participants who received the study intervention with at least 1 day of e-diary data transmitted.

Arm	Measure	Group	Value (NUMBER)
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Fatigue: Mild	18.2 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Muscle Pain: Severe	0 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Fatigue: Moderate	18.2 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Joint Pain: Mild	7.1 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Diarrhea: Severe	0.7 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Joint Pain: Moderate	5.1 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Fatigue: Severe	0.9 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Joint Pain: Severe	0.2 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Fever: 38.0°C to 38.4°C	0.4 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Nausea: Mild	9.3 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Nausea: Moderate	2.4 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Headache: Mild	20.8 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Nausea: Severe	0 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Muscle Pain: Mild	15.7 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Vomiting: Mild	1.6 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Headache: Moderate	7.3 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Vomiting: Moderate	0.4 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Fever: >38.4°C to 38.9°C	1.1 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Vomiting: Severe	0 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Headache: Severe	0.2 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Diarrhea: Mild	11.1 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Diarrhea: Moderate	3.1 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Fever: >38.9°C to 40.0°C	0 Percentage of participants
SSA: RSVpreF	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Muscle Pain: Moderate	8.6 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Diarrhea: Severe	0.9 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Fatigue: Mild	22.2 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Nausea: Mild	8.9 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Fever: 38.0°C to 38.4°C	0.4 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Fever: >38.4°C to 38.9°C	0.9 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Fatigue: Moderate	15.6 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Fatigue: Severe	0.4 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Headache: Mild	18.7 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Headache: Moderate	11.6 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Headache: Severe	0 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Muscle Pain: Mild	9.8 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Muscle Pain: Moderate	6.2 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Muscle Pain: Severe	0 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Joint Pain: Mild	4.0 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Joint Pain: Moderate	6.2 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Joint Pain: Severe	0 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Nausea: Moderate	0.9 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Nausea: Severe	0.4 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Vomiting: Mild	0.4 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Vomiting: Moderate	0.9 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Vomiting: Severe	0 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Diarrhea: Mild	12.4 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Diarrhea: Moderate	3.6 Percentage of participants
SSA: Placebo	SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination	Fever: >38.9°C to 40.0°C	0 Percentage of participants

Primary

SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 1

GMT of RSV A and RSV B before vaccination were reported in this outcome measure. Assay results below the lower limit of quantification (LLOQ) were set to 0.5\*LLOQ. GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution).

Time frame: 1 Month After Vaccination 1 (on Day 1)

Population: Evaluable immunogenicity population included all eligible participants for SSB who received 2 dose of RSVpreF; (blood collected for 1 month after last dose to be 27-42 days after second dose of RSVpreF; had at least 1 valid, determinate assay result 1 month after vaccination (1 month after second dose of RSVpreF); had no major protocol violations from vaccination through 1-month postvaccination blood draw (1 month after second dose of RSVpreF).

Arm	Measure	Group	Value (GEOMETRIC_MEAN)
SSA: RSVpreF	SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 1	RSV A	26173 Titer
SSA: RSVpreF	SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 1	RSV B	24701 Titer
SSA: Placebo	SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 1	RSV A	26075 Titer
SSA: Placebo	SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 1	RSV B	25384 Titer

Primary

SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 2

Time frame: 1 Month After Vaccination 2 (1-month post Vaccination 1)

Arm	Measure	Group	Value (GEOMETRIC_MEAN)
SSA: RSVpreF	SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 2	RSV A	21910 Titer
SSA: RSVpreF	SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 2	RSV B	20936 Titer
SSA: Placebo	SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 2	RSV A	25159 Titer
SSA: Placebo	SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 2	RSV B	22774 Titer

Primary

SSB: GMT of NT for RSV A and RSV B Before Vaccination 1

Time frame: Before Vaccination 1 (on Day 1)

Arm	Measure	Group	Value (GEOMETRIC_MEAN)
SSA: RSVpreF	SSB: GMT of NT for RSV A and RSV B Before Vaccination 1	RSV A	2943 Titer
SSA: RSVpreF	SSB: GMT of NT for RSV A and RSV B Before Vaccination 1	RSV B	2584 Titer
SSA: Placebo	SSB: GMT of NT for RSV A and RSV B Before Vaccination 1	RSV A	3289 Titer
SSA: Placebo	SSB: GMT of NT for RSV A and RSV B Before Vaccination 1	RSV B	2992 Titer

Primary

SSB: Percentage of Participants With AEs From Vaccination 1 Through 1 Month After Vaccination 2

Time frame: From Vaccination 1 (on Day 1) through 1 month after Vaccination 2 (1 month after Vaccination 1) [approximately up to maximum of 2 months]

Population: Safety population included all enrolled participants who received the study intervention.

Arm	Measure	Value (NUMBER)
SSA: RSVpreF	SSB: Percentage of Participants With AEs From Vaccination 1 Through 1 Month After Vaccination 2	13.5 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With AEs From Vaccination 1 Through 1 Month After Vaccination 2	22.4 Percentage of participants

Primary

SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1

Local reactions included pain at injection site, redness and swelling, recorded by participants in an e-diary. Pain at injection site was graded as mild: did not interfere with activity; moderate: interfered with activity and severe: prevented daily activity. Redness and swelling were measured and recorded in measuring device units, where 1 measuring device unit=0.5 cm. Redness and swelling were graded as mild: \> 2.0 cm to 5.0 cm; moderate: \> 5.0 cm to 10.0 cm and severe: \> 10 cm.

Time frame: Within 7 Days after Vaccination 1 (Vaccination 1 on Day 1)

Population: E-diary safety population included all participants who received the first dose of RSVpreF and had at least 1 day of e-diary data transferred during the Dose 1 e-diary collection period.

Arm	Measure	Group	Value (NUMBER)
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Pain at injection site: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Redness: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Pain at injection site: Moderate	1.0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Swelling: Mild	6.3 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Redness: Mild	5.2 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Swelling: Moderate	2.1 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Pain at injection site: Mild	25.0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Swelling: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Redness: Moderate	1.0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Swelling: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Pain at injection site: Mild	16.8 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Pain at injection site: Moderate	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Pain at injection site: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Redness: Mild	1.9 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Redness: Moderate	1.9 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Redness: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Swelling: Mild	0.9 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1	Swelling: Moderate	1.9 Percentage of participants

Primary

SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2

Local reactions included pain at injection site, redness and swelling, recorded by participants in an e-diary. Pain at injection site was graded as mild: did not interfere with activity; moderate: interfered with activity and severe: prevented daily activity. Redness and swelling were measured and recorded in measuring device units, where 1 measuring device unit = 0.5 cm. Redness and swelling were graded as mild: \>2.0 cm to 5.0 cm; moderate: \>5.0 cm to 10.0 cm and severe: \>10 cm.

Time frame: Within 7 Days after Vaccination 2 (Vaccination 2: 1-month post-vaccination 1 on Day 1)

Population: E-diary safety population included all participants who received 2 doses of RSVpreF and had at least 1 day of e-diary data transferred during the Dose 2 e-diary collection period. Here, 'Overall Number of Participants Analyzed' (N)= participants evaluable for this outcome measure.

Arm	Measure	Group	Value (NUMBER)
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Pain at injection site: Moderate	4.3 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Redness: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Redness: Mild	2.1 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Swelling: Mild	2.1 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Pain at injection site: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Swelling: Moderate	1.1 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Redness: Moderate	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Swelling: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Pain at injection site: Mild	42.6 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Swelling: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Pain at injection site: Mild	29.5 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Pain at injection site: Moderate	1.9 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Pain at injection site: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Redness: Mild	1.9 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Redness: Moderate	1.9 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Redness: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Swelling: Mild	3.8 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2	Swelling: Moderate	5.7 Percentage of participants

Primary

SSB: Percentage of Participants With NDCMCs From Vaccination Throughout the Study

Time frame: From Vaccination 1 (on Day 1) through 6 months after Vaccination 2 (1 month after Vaccination 1) [approximately up to maximum of 7 months]

Population: Safety population included all enrolled participants who received the study intervention.

Arm	Measure	Value (NUMBER)
SSA: RSVpreF	SSB: Percentage of Participants With NDCMCs From Vaccination Throughout the Study	2.1 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With NDCMCs From Vaccination Throughout the Study	6.5 Percentage of participants

Primary

SSB: Percentage of Participants With SAEs Throughout the Study

Time frame: From Vaccination 1 (on Day 1) through 6 months after Vaccination 2 (1 month after Vaccination 1) [approximately up to maximum of 7 months]

Population: Safety population included all enrolled participants who received the study intervention.

Arm	Measure	Value (NUMBER)
SSA: RSVpreF	SSB: Percentage of Participants With SAEs Throughout the Study	7.3 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With SAEs Throughout the Study	14.0 Percentage of participants

Primary

SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1

Time frame: Within 7 Days after Vaccination 1 (Vaccination 1 on Day 1)

Population: E-diary safety population included all participants who received the first dose of RSVpreF and had at least 1 day of e-diary data transferred during the Dose 1 e-diary collection period.

Arm	Measure	Group	Value (NUMBER)
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Fever: >38.9°C to 40.0°C	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Nausea: Mild	9.4 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Headache: Moderate	9.4 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Nausea: Moderate	3.1 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Fatigue: Moderate	16.7 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Nausea: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Headache: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Diarrhea: Mild	15.6 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Diarrhea: Moderate	6.3 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Fever: >38.4°C to 38.9°C	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Diarrhea: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Vomiting: Mild	4.2 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Muscle Pain: Mild	18.8 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Fatigue: Severe	2.1 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Muscle Pain: Moderate	7.3 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Fatigue: Mild	20.8 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Muscle Pain: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Vomiting: Moderate	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Joint Pain: Mild	10.4 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Headache: Mild	29.2 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Joint Pain: Moderate	7.3 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Vomiting: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Joint Pain: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Fever: 38.0°C to 38.4°C	1.0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Joint Pain: Severe	1.9 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Fever: 38.0°C to 38.4°C	0.9 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Fever: >38.4°C to 38.9°C	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Fever: >38.9°C to 40.0°C	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Fatigue: Mild	19.6 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Fatigue: Moderate	22.4 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Fatigue: Severe	2.8 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Headache: Mild	15.0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Headache: Moderate	6.5 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Headache: Severe	0.9 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Vomiting: Mild	0.9 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Diarrhea: Mild	12.1 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Vomiting: Moderate	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Vomiting: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Nausea: Mild	3.7 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Nausea: Moderate	4.7 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Nausea: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Diarrhea: Moderate	5.6 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Diarrhea: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Muscle Pain: Mild	13.1 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Muscle Pain: Moderate	5.6 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Muscle Pain: Severe	1.9 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Joint Pain: Mild	11.2 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1	Joint Pain: Moderate	8.4 Percentage of participants

Primary

SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2

Time frame: Within 7 Days after Vaccination 2 (Vaccination 2: 1-month post-vaccination 1 on Day 1)

Population: E-diary safety population included all participants who received 2 doses of RSVpreF and had at least 1 day of e-diary data transferred during the Dose 2 e-diary collection period. Here, 'N'= participants evaluable for this outcome measure.

Arm	Measure	Group	Value (NUMBER)
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Nausea: Mild	5.3 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Headache: Mild	13.8 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Nausea: Moderate	1.1 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Fever: >38.4°C to 38.9°C	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Nausea: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Headache: Moderate	10.6 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Diarrhea: Mild	6.4 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Fatigue: Mild	19.1 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Diarrhea: Moderate	5.3 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Headache: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Diarrhea: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Fatigue: Moderate	18.1 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Muscle Pain: Mild	16.0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Vomiting: Mild	2.1 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Muscle Pain: Moderate	3.2 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Fever: 38.0°C to 38.4°C	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Muscle Pain: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Vomiting: Moderate	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Joint Pain: Mild	8.5 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Fatigue: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Joint Pain: Moderate	3.2 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Vomiting: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Joint Pain: Severe	0 Percentage of participants
SSA: RSVpreF	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Fever: >38.9°C to 40.0°C	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Joint Pain: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Fever: 38.0°C to 38.4°C	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Fever: >38.4°C to 38.9°C	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Fever: >38.9°C to 40.0°C	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Fatigue: Moderate	19.0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Fatigue: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Headache: Mild	19.0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Headache: Moderate	5.7 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Headache: Severe	1.0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Vomiting: Mild	1.0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Vomiting: Moderate	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Vomiting: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Nausea: Mild	5.7 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Nausea: Moderate	1.0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Nausea: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Diarrhea: Mild	10.5 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Diarrhea: Moderate	2.9 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Diarrhea: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Muscle Pain: Mild	15.2 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Muscle Pain: Moderate	8.6 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Muscle Pain: Severe	0 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Joint Pain: Mild	12.4 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Joint Pain: Moderate	4.8 Percentage of participants
SSA: Placebo	SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2	Fatigue: Mild	23.8 Percentage of participants

Secondary

SSA: GMFR of NTs for RSV A and RSV B From Before Vaccination to 1 Month After Vaccination

GMFRs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution).

Time frame: SSA: Before Vaccination (on Day 1) and 1 Month After Vaccination

Population: Evaluable immunogenicity population=participants who met following criteria:(i)eligible for Substudy A;(ii)received study interventions (RSVpreF or placebo)to which they were randomized;(iii)had 1-month postvaccination blood collected 27-42days after vaccination;(iv) had at least 1 valid,determinate assay result 1month after vaccination;(v)had no major protocol violations from vaccination through 1-month postvaccination blood draw. Here,'Number Analyzed'=participants evaluable at specified rows.

Arm	Measure	Group	Value (GEOMETRIC_MEAN)
SSA: RSVpreF	SSA: GMFR of NTs for RSV A and RSV B From Before Vaccination to 1 Month After Vaccination	RSV A	17.5 Fold rise
SSA: RSVpreF	SSA: GMFR of NTs for RSV A and RSV B From Before Vaccination to 1 Month After Vaccination	RSV B	18.5 Fold rise
SSA: Placebo	SSA: GMFR of NTs for RSV A and RSV B From Before Vaccination to 1 Month After Vaccination	RSV A	1.0 Fold rise
SSA: Placebo	SSA: GMFR of NTs for RSV A and RSV B From Before Vaccination to 1 Month After Vaccination	RSV B	1.0 Fold rise

Secondary

SSA: GMT of NTs for RSV A and RSV B Before Vaccination and 1 Month After Vaccination

GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution).

Time frame: SSA: Before Vaccination (on Day 1) and 1 Month After Vaccination

Arm	Measure	Group	Value (GEOMETRIC_MEAN)
SSA: RSVpreF	SSA: GMT of NTs for RSV A and RSV B Before Vaccination and 1 Month After Vaccination	RSV A: Before Vaccination	2388 Titer
SSA: RSVpreF	SSA: GMT of NTs for RSV A and RSV B Before Vaccination and 1 Month After Vaccination	RSV A: 1 month after vaccination	41595 Titer
SSA: RSVpreF	SSA: GMT of NTs for RSV A and RSV B Before Vaccination and 1 Month After Vaccination	RSV B: Before Vaccination	2075 Titer
SSA: RSVpreF	SSA: GMT of NTs for RSV A and RSV B Before Vaccination and 1 Month After Vaccination	RSV B: 1 month after vaccination	38450 Titer
SSA: Placebo	SSA: GMT of NTs for RSV A and RSV B Before Vaccination and 1 Month After Vaccination	RSV B: 1 month after vaccination	2135 Titer
SSA: Placebo	SSA: GMT of NTs for RSV A and RSV B Before Vaccination and 1 Month After Vaccination	RSV A: Before Vaccination	2797 Titer
SSA: Placebo	SSA: GMT of NTs for RSV A and RSV B Before Vaccination and 1 Month After Vaccination	RSV B: Before Vaccination	2230 Titer
SSA: Placebo	SSA: GMT of NTs for RSV A and RSV B Before Vaccination and 1 Month After Vaccination	RSV A: 1 month after vaccination	2660 Titer

Secondary

SSB: Geometric Mean Fold Rise (GMFR) of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 1

GMFRs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution).

Time frame: At 1 Month After Vaccination 1 (on Day 1) to 1 Month Post-Vaccination 1

Arm	Measure	Group	Value (GEOMETRIC_MEAN)
SSA: RSVpreF	SSB: Geometric Mean Fold Rise (GMFR) of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 1	RSV A	8.8 Fold rise
SSA: RSVpreF	SSB: Geometric Mean Fold Rise (GMFR) of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 1	RSV B	9.6 Fold rise
SSA: Placebo	SSB: Geometric Mean Fold Rise (GMFR) of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 1	RSV A	7.9 Fold rise
SSA: Placebo	SSB: Geometric Mean Fold Rise (GMFR) of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 1	RSV B	8.5 Fold rise

Secondary

SSB: GMFR of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 2

GMFRs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution).

Time frame: At 1 Month After Vaccination 1 (on Day 1) to 1 Month Post-Vaccination 2

Population: Evaluable immunogenicity population was analyzed.

Arm	Measure	Group	Value (GEOMETRIC_MEAN)
SSA: RSVpreF	SSB: GMFR of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 2	RSV A	7.4 Fold rise
SSA: RSVpreF	SSB: GMFR of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 2	RSV B	8.1 Fold rise
SSA: Placebo	SSB: GMFR of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 2	RSV A	7.7 Fold rise
SSA: Placebo	SSB: GMFR of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 2	RSV B	7.6 Fold rise

Source: ClinicalTrials.gov · Data processed: Feb 5, 2026

A Study to Assess the Safety, Tolerability, and Immunogenicity of RSVpreF in Adults at High Risk of Severe RSV Disease

Conditions

Keywords

Brief summary

Detailed description

Related papers

Interventions

Sponsors

Study design

Masking description

Intervention model description

Eligibility

Inclusion criteria

Exclusion criteria

Design outcomes

Primary

Secondary

Countries

Participant flow

Recruitment details

Pre-assignment details

Participants by arm

Withdrawals & dropouts

Baseline characteristics

Adverse events

Outcome results

SSA: Geometric Mean Ratio (GMR) Estimated by Ratio of the Geometric Mean Titers (GMTs) at 1 Month After Vaccination in Study C3671023 Participants Compared to Study C3671013 Adults >= 60 Years

SSA: Percentage of Participants With Adverse Events (AEs) From Vaccination Through 1 Month After Vaccination

SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination

SSA: Percentage of Participants With Newly Diagnosed Chronic Medical Conditions (NDCMCs) From Vaccination Throughout the Study

SSA: Percentage of Participants With Serious Adverse Events (SAEs) Throughout the Study

SSA: Percentage of Participants With Seroresponse Rate and Difference in Seroresponse Rates of RSV A and RSV B Serum NTs at 1 Month After Vaccination for Participants in Study C3671023 and C3671013 Adults >= 60 Years

SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination

SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 1

SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 2

SSB: GMT of NT for RSV A and RSV B Before Vaccination 1

SSB: Percentage of Participants With AEs From Vaccination 1 Through 1 Month After Vaccination 2

SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1

SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2

SSB: Percentage of Participants With NDCMCs From Vaccination Throughout the Study

SSB: Percentage of Participants With SAEs Throughout the Study

SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1

SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2

SSA: GMFR of NTs for RSV A and RSV B From Before Vaccination to 1 Month After Vaccination

SSA: GMT of NTs for RSV A and RSV B Before Vaccination and 1 Month After Vaccination

SSB: Geometric Mean Fold Rise (GMFR) of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 1

SSB: GMFR of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 2