Study type

Study type

Non-interventional study
Study drug and medical condition

Name of medicine

ABRYSVO
Population studied

Short description of the study population

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; Refer to Section 9.1.).
3. Hospitalised with ARI 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. See Section 9.3.2. for ARI hospitalisation definition.
4. Infant date of birth on or after 17 February 2025 (≥14 days after start of the first national ABRYSVO vaccination campaign to ensure potential to have been born to an ABRYSVO-vaccinated mother).
5. Infant born to a birth mother eligible to receive ABRYSVO vaccination *h
...

*h: Birth mothers who were expected (based on estimated date of delivery) to reach ≥28 ⁰⁄₇ wGA on or after
03 February 2025.

Exclusion Criteria
Participants meeting any of the following criteria will not be included in the study:
1. Infant born at <28⁰⁄₇ weeks of gestational age.
1. Infant received any licensed or investigational RSV preventive product (e.g., palivizumab, nirsevimab, active RSV vaccine) since birth.
2. Infant received ≥1 blood transfusion or other blood products containing antibody (e.g., fresh frozen plasma) since birth.
3. Infant born to a birth mother who received any other licensed or investigational RSV vaccine during this pregnancy.
4. Infant born to a birth mother for whom ABRYSVO vaccination status cannot be confirmed in available data sources.
Study design details

Study design

This retrospective NI study will be conducted within a research network comprised of independent hospitals across Australia using data collected during routine
SOC clinical encounters available in health records,
supplemented with information from the official national immunisation registry, AIR.

Main study objective

Primary Research Question: What is the real-world effectiveness of ABRYSVO vaccination during pregnancy against respiratory syncytial virus (RSV)-associated outcomes in infants in Australia?

Primary Research Objective: 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 using a case-control study with a test negative design (TND).

Setting

This hospital-based retrospective study will be conducted in a research network of up to 9 independent hospitals across 6 states/territories in Australia. A list of each hospital, with accompanying details, will be provided in the statistical analysis plan (SAP).
Given the retrospective nature of this study, hospitals that already function as national sentinel units for respiratory virus surveillance, or that have robust clinical, laboratory or epidemiological surveillance will be included. Each participating hospital conducts year-round SOC testing for ARI which includes respiratory virus panel test using polymerase chain reaction (PCR).