Maternal RSVpreF vaccination prevented most infant RSV admissions in real-world use

Design

Test-negative case-control study, 9 hospitals

Population

655 infants ≤6 months hospitalised with lower respiratory tract disease, Australia

Primary outcome

Hospitalisation for RSV lower respiratory tract disease

Effect

VE 77.8% (95% CI 66.4–85.3) to 6 months; 86.3% (79.0–91.1) to 2 months; severe disease 80.4% (54.4–91.6)

Australia added maternal RSVpreF vaccination from 28 weeks' gestation to its national programme in February 2025, year-round. This test-negative case-control study covered 9 hospitals with routine respiratory testing from March 2025 to February 2026. It included 655 infants aged 6 months or younger admitted with lower respiratory tract disease. It was published in August 2026.

Vaccine effectiveness against hospitalisation for RSV lower respiratory tract disease was 77.8% up to 6 months, 80.2% up to 3 months and 86.3% up to 2 months. It was 68.2% between 2 and 4 months. Protection against severe disease (80.4%) was similar. Effectiveness did not vary with gestation at vaccination or the interval before delivery, and co-administration with other pregnancy vaccines did not reduce it.

This turns trial efficacy into real-world evidence from a whole national programme. The protection is strongest in the youngest infants, who are most likely to need admission. For India, maternal RSV vaccine availability and CDSCO approval should be confirmed; where it is not available, the evidence supports advocating for access rather than changing individual practice today.

• Offer maternal RSV vaccination from 28 weeks where it is available and approved
• Give it at least 14 days before expected delivery
• Co-administer with other pregnancy vaccines if convenient; effectiveness was unchanged
• Counsel that protection wanes after 2 to 4 months
• Confirm local regulatory status before recommending

Why it matters

Maternal vaccination protects infants against RSV admission as well in a national programme as it did in trials.

Don't overread it

This was a test-negative observational study in the first programme year; long-term safety, including preterm birth, was not assessed here.

The statistics, in plain English

Vaccine effectiveness of 77.8% (95% CI 66.4–85.3) means vaccinated mothers' babies had about a fifth of the odds of RSV admission. Test-negative designs compare RSV-positive with RSV-negative admitted infants, which controls for healthcare-seeking behaviour but remains observational. The lower estimate at 2 to 4 months has a wider interval (42.2–82.5), consistent with waning maternal antibody.

Read the rest in the app

You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.

Get Daily Doctor — free

Scan to keep reading on your phone. No account needed to start.