BronchStop Study Protocol, Season 2

Area of Science:

• Pediatrics
• Immunology
• Public Health

Background:

• Serious respiratory tract infections in children increased post-lockdown, prompting the BronchStart study.
• BronchStart data informed the UK's Joint Committee on Vaccination and Immunisation (JCVI) recommendation for maternal respiratory syncytial virus (RSV) vaccination.
• Maternal RSV vaccination was rolled out in the UK in August/September 2024 for pregnant women at ≥28 weeks gestation.

Purpose of the Study:

• To assess the effectiveness of maternal RSV vaccination against infant hospitalization for RSV-associated acute lower respiratory tract infection (ALRI).
• To understand factors influencing maternal vaccine uptake through a survey administered to mothers.
• To investigate residual causes of severe infant respiratory disease in the post-vaccination era.

Main Methods:

• A UK-wide, multi-centre, prospective, test-negative case control study will be conducted in the 2025-2026 winter season.
• Infants under 6 months born to vaccinated mothers will be recruited.
• Maternal surveys, vaccination record access, and infant virological sample analysis (whole genome sequencing, rRT-PCR) will be employed.

Main Results:

• This section is not applicable as the study is prospective and results are not yet available.

Conclusions:

• This study will provide crucial data on the effectiveness of maternal RSV vaccination in protecting infants against severe respiratory illness.
• Findings will inform ongoing public health policy and vaccination strategies, including recommendations to advisory groups like JCVI and the World Health Organization.