STudy of Real World vaccinE Effectiveness of maTernal RSVpreF vaccinatiON Against Respiratory Syncytial Virus (RSV) in Hospitalised Infants in Australia (STREETON)

Launched by PFIZER · Aug 7, 2025

Keywords

ClinConnect Summary

This study, called STREETON, is looking at how well a vaccine given to pregnant women (called RSVpreF or ABRYSVO) protects their babies from getting very sick with a common lung infection called Respiratory Syncytial Virus (RSV). RSV can cause serious breathing problems in infants, especially those under one year old. Researchers will use existing health records from hospitals across Australia, along with vaccination information from a national registry and lab test results, to see if babies born to vaccinated mothers have fewer or less severe RSV infections that require hospital stays.

To be part of this study, babies must be under one year old when hospitalized for a breathing illness and have been tested for RSV around the time they were admitted. The babies’ mothers must have been eligible to receive the RSV vaccine during pregnancy, and the baby’s birth date must be on or after February 17, 2025. Babies born very early (before 28 weeks of pregnancy), who have received other RSV treatments or blood products containing antibodies, or whose mothers received other RSV vaccines during pregnancy won’t be included. Since this study uses only existing medical records, there is no direct contact or extra tests for the babies or families involved. The goal is to understand how effective the maternal vaccine is in real life at protecting infants from RSV-related hospital visits.

Gender

ALL

Eligibility criteria

• 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.