Prevention of primary CMV infection
Conditions
Interventions
Participants will be randomly assigned to receive a single injection of either mRNA-1647 vaccine at the selected dose or placebo in a 1:1 randomization ratio. Investigational product will be administe
Sponsors
Oki Kosuke
Eligibility
Sex/Gender
Female
Inclusion criteria
Inclusion criteria: Participants aged 20 years or over, has or anticipates having direct exposure within 7 months after the planned first dose (in the home, socially, or occupationally) to at least 1 child 5 years or under of age. Direct exposure is defined as either participant is the parent, or participant has close contact (feeding, diaper changes, childcare/supervision) for at least 8 hours per week. CMV-seronegative Cohort is CMV-seronegative based on CMV testing at Screening. CMV-seropositive Cohort is CMV-seropositive based on CMV testing at Screening. Investigator assessment confirms that the participant (including in the case of an emancipated minor), or parent(s)/legally acceptable representative (LAR)(s), as applicable, understand and are willing and physically able to comply with protocol-mandated follow-up including all study visits and procedures anticipated during the 30 month study period. Female participants: Urine pregnancy test is negative at Screening and negative on the day of the first injection (Day 1). If the participant is sexually active, has practiced adequate contraception for at least 28 days prior to the first injection (Day 1) and agrees to continue adequate contraception through 3 months following the third study injection (Month 9/Day 257). Extension substudy: All consenting participants who were CMV-seronegative at Baseline in the mRNA-1647-P301 main study (including those who did seroconvert and did not seroconvert during the main study), received at least one study injection in the main study but did not withdraw study consent, and completed the final study visit in mRNA-1647-P301 main study. Consenting participants in mRNA-1647 P301 main study who were CMV seropositive at Baseline, received all 3 study injections, did not withdraw study consent, and completed the final study visit in the main study.
Exclusion criteria
Exclusion criteria: History of a diagnosis or condition that, in the judgment of the Investigator, is clinically unstable or may affect participant safety, assessment of safety endpoints, assessment of immune response, or adherence to study procedures. Received or plans to receive any nonstudy vaccine less than 28 days prior to and after any study injection; in addition, the following criteria for COVID-19 and influenza vaccines apply: Any Coronavirus disease 2019 (COVID-19) vaccination series must have been completed a minimum 28 days prior to receiving any dose of the study injection. COVID-19 vaccines (regardless of manufacturer) must be administered at least 28 days prior to or after any study injection. Influenza vaccines may be administered more than 14 days prior to or after any study injection. Received systemic immunosuppressants or immune-modifying drugs for more than 14 days in total within 6 months prior to the day of first injection (Day 1) (for corticosteroids, 5 milligrams (mg)/day or over of prednisone equivalent) or plans to do so during the course of the study. Inhaled, nasal, and topical steroids are allowed. Stable immunomodulator regimens used for managing environmental allergies are allowed. Receipt of an antiviral with activity against CMV (ganciclovir, valganciclovir, foscarnet, cidofovir, letermovir, acyclovir, valacyclovir) less than 2 weeks prior to the day of first injection or plans to do so during the course of the study. Previous receipt of an investigational CMV vaccine. Receipt of systemic immunoglobulins or blood products less than 3 months prior to the day of first injection. Participated in an interventional clinical study less than 28 days prior to the day of first injection (Day 1) or plans to do so while enrolled in this study. Participant has donated 450 milliliters (mL) or over of blood products less than 28 days prior to Screening. Participant is a member of study team or is an immediate family member or household member of study personnel. Extension substudy: Receipt of any CMV vaccine other than mRNA-1647. Diagnosis or condition that, in the judgment of the Investigator, may affect participant safety, assessment of safety endpoints, assessment of immune response, or adherence to study procedures, including any medical, psychiatric, or occupational condition that, in the opinion of the Investigator, might pose additional risk due to participation in the study or could interfere with the interpretation of study results.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Seroconversion From a Negative to a Positive Result for Serum Immunoglobulin G (IgG) Against Antigens not Encoded by mRNA-1647 [Time Frame: Day 197 (28 days after the third injection) up to Day 887 (24 months after the third injection)] Number of Participants With Solicited Adverse Reactions (ARs) [Time Frame: Up to 176 days (7 days after each injection)] Number of Participants With Unsolicited Adverse Events (AEs) [Time Frame: Up to 197 days (28 days after each injection)] Number of Participants With Medically-Attended Adverse Events (MAAEs) [Time Frame: Day 1 through 6 months after the last injection (up to 347 days)] Number of Participants With Adverse Event of Special Interests (AESIs) and Serious Adverse Events (SAEs) [Time Frame: Day 1 through Month 30] Geometric Mean Titers (GMTs) of Antigen-Specific Neutralizing Antibody (nAb) [Time Frame: Month 30 up to Month 54] Geometric Mean Concentration (GMC) of Binding Antibody [Time Frame: Month 30 up to Month 54] Seroconversion From a Negative to a Positive Result for Serum IgG Against Antigens not Encoded by mRNA-1647 [Month 30 up to Month 54] Number of Participants With Systemic Viral Dissemination [Time Frame: Month 30 up to Month 54] | — |
Secondary
| Measure | Time frame |
|---|---|
| GMTs of Antigen-Specific nAb [Time Frame: Day 1, Months 3, 7, 12, 18, 24, and 30] GMC of Antigen-Specific Binding Antibody [Time Frame: Day 1, Months 3, 7, 12, 18, 24, and 30] Number of Participants with AEs leading to Study Discontinuation, SAEs and Deaths [Time Frame: Month 30 up to Month 54] Number of Participants With Systemic Viral Dissemination [Time Frame: Day 1 through Month 30] Number of Participants With Positive Urine CMV Polymerase Chain Reaction (PCR) Results Post Seroconversion [Time Frame: Day 1 through Month 30] Number of Participants With Positive Urine CMV PCR Results Post Seroconversion [Time Frame: Month 30 up to Month 54] | — |
Countries
Australia, Belgium, Canada, Estonia, Finland, France, Germany, Israel, Italy, Japan, Spain, United Kingdom, United States
Contacts
Public ContactKosuke Oki
PPD-SNBL K.K.
Outcome results
None listed