Acute Respiratory Illness (ARI), Lower Respiratory Tract Disease, Respiratory Syncytial Virus, Respiratory Syncytial Virus (RSV), Respiratory Tract Diseases
Conditions
Keywords
RSVpreF, Vaccine, Effectiveness, Vaccine Effectiveness, Pregnancy, Maternal, Immunization, Maternal Immunization, ABRYSVO, Respiratory Syncytial Virus, Lower Respiratory Tract Disease, Infants, Hospitalized, Hospitalization, Test Negative Design, Case Control, Retrospective, Respiratory Outcomes, Prefusion F protein-based, Acute Respiratory Illness
Brief summary
This Pfizer-sponsored real-world retrospective non-interventional study will be conducted within a research network comprised of independent hospitals across Australia using data collected during routine standard of care clinical encounters available in health records, supplemented with information from the official national immunisation registry, the Australian Immunisation Register. Additional data from accredited pathology laboratories will be included. There will be no active enrollment of study participants, no direct contact with study participants, and no collection of any primary data outside of the standard of care. This study will use a test negative design to evaluate real-world vaccine effectiveness of RSVpreF vaccination during pregnancy against RSV-associated outcomes in infants.
Detailed description
This case-control study using a test negative design will include all infants through 12 months of age who were admitted to one of the participating hospitals with symptoms of respiratory infection, met the clinical case definition of acute respiratory illness, and had a respiratory specimen collected within 10 days prior to hospital admission through 3 days after a hospital admission with an RSV test result through standard of care testing. The primary objective is to estimate vaccine effectiveness (VE) of ABRYSVO during pregnancy against RSV-positive lower respiratory tract disease (LRTD) hospitalisation among infants from birth through 6 months (0 to ≤180 days) of age. Baseline characteristics of the study population will be described by case/control status and by maternal RSVpreF vaccination status. Standardised mean differences may be used to compare the distributions (absolute differences \>0.10 will be considered meaningful). For all VE objectives, we will use a logistic regression model to compare the odds of maternal ABRYSVO vaccination during pregnancy between test-positive cases and test-negative controls, generating an odds ratio (OR) and 95% CI and we will use multivariable logistic regression to compute an adjusted OR (aOR), from which we will derive final VE estimates, adjusted for potential confounding, according to the formula: VE = (1-aOR) x 100%.
Interventions
BIOLOGICALABRYSVO
This is a non-interventional retrospective study; therefore, ABRYSVO vaccine has already been administered according to the standard of care. ABRYSVO is a bivalent RSV prefusion F protein-based vaccine (RSVpreF) composed of two prefusion F proteins to protect against both RSV-A and RSV-B.
Sponsors
The Kids Research Institute Australia on behalf of the Centre for Child Health Research, University of Western Australia
Pfizer
Study design
Observational model
CASE_CONTROL
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
0 Years to 12 Months
Healthy volunteers
No
Inclusion criteria
Participants must meet all of the following inclusion criteria to be eligible for inclusion in the study: 1. Infant ≤12 months (≤360 days) of age on the hospitalisation date. 2. Index date within the time period for data collection (approximately 01 March 2025 - 28 February 2027) 3. Hospitalised with acute respiratory illness meeting the protocol-defined clinical case definition, and for whom RSV testing results from a specimen collected 10 days prior to hospital admission through 3 days after a hospital admission are known. 4. Infant born to a birth mother eligible to receive ABRYSVO vaccination, with infant date of birth on or after 17 February 2025.
Exclusion criteria
Participants meeting any of the following criteria will not be included in the study: 1. Infant born at \<28 weeks and 0/7 days of gestational age. 2. Infant received any licensed or investigational RSV preventive product (e.g., palivizumab, nirsevimab, active RSV vaccine) since birth. 3. Infant received ≥1 blood transfusion or other blood products containing antibody (e.g., fresh frozen plasma) since birth. 4. Infant born to a birth mother who received any other licensed or investigational RSV vaccine during this pregnancy. 5. Infant born to a birth mother for whom ABRYSVO vaccination status cannot be confirmed in available data sources.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Estimate vaccine effectiveness of ABRYSVO during pregnancy against RSV-positive lower respiratory tract disease hospitalisation among infants. | From birth through 6 months (0 to ≤180 days) of age. | RSV-positive lower respiratory tract disease hospitalisation occurring 0 to ≤180 days after birth. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Estimate vaccine effectiveness of ABRYSVO during pregnancy against RSV-positive lower respiratory tract disease hospitalisation among infants. | From birth through 6 months (0 to ≤180 days) of age within key subgroups. | RSV-positive lower respiratory tract disease hospitalisation occurring 0 to ≤180 days after birth subgrouped by: * gestational age at ABRYSVO vaccination. * gestational age at birth. * time from ABRYSVO vaccination to birth. * time intervals of infant age at illness, including cumulative (e.g., 0 to ≤3 months, 0 to ≤6 months) and discrete (e.g., 0 to ≤3 months, \>3 to ≤6 months) age intervals. |
| Estimate vaccine effectiveness of ABRYSVO during pregnancy against RSV-positive severe lower respiratory tract disease hospitalisation among infants. | From birth through 6 months (0 to ≤180 days) of age and within key subgroups. | RSV-positive lower respiratory tract disease hospitalisation occurring 0 to ≤180 days after birth subgrouped by: * gestational age at ABRYSVO vaccination. * gestational age at birth. * time from ABRYSVO vaccination to birth. * time intervals of infant age at illness, including cumulative (e.g., 0 to ≤3 months, 0 to ≤6 months) and discrete (e.g., 0 to ≤3 months, \>3 to ≤6 months) age intervals. |
| Estimate vaccine effectiveness of ABRYSVO during pregnancy against RSV-positive acute respiratory illness hospitalisation among infants. | From birth through 6 months (0 to ≤180 days) of age and within key subgroups. | RSV-positive acute respiratory illness hospitalisation occurring 0 to ≤180 days after birth subgrouped by: * gestational age at ABRYSVO vaccination. * gestational age at birth. * time from ABRYSVO vaccination to birth. * time intervals of infant age at illness, including cumulative (e.g., 0 to ≤3 months, 0 to ≤6 months) and discrete (e.g., 0 to ≤3 months, \>3 to ≤6 months) age intervals. |
Countries
Australia
Outcome results
None listed