RSV Bivalent Prefusion F Protein Vaccine in Pregnancy and Protection Against RSV-Associated Illness in Infants: A Systematic Review and Meta-Analysis.

In 30 seconds

This systematic review and meta-analysis assessed real-world effectiveness of maternal RSV bivalent prefusion F protein vaccination in preventing RSV-associated lower respiratory tract infection (LRTI) hospitalization in infants. It included 7 nonrandomized studies from Argentina, the UK, and the US, comprising 7112 infants, including 2684 born to vaccinated mothers. When vaccination occurred at least 14 days before delivery, pooled effectiveness against hospitalization was 82% (95% CI, 81%-82%) from birth to 3 months and 78% (95% CI, 70%-84%) from birth to 6 months. The authors concluded that postimplementation evidence supports protection during the first 6 months of life.

Key findings

• Effectiveness against RSV-associated LRTI hospitalization from birth to 3 months was 82% (95% CI, 81%-82%; 3 studies, 4397 participants; I2 = 0%).
• Effectiveness from birth to 6 months was 78% (95% CI, 70%-84%; 6 studies, 3008 participants; I2 = 18.7%).
• The pooled estimates applied when maternal vaccination occurred 14 days or more before delivery.
• Available data were insufficient to meta-analyze effectiveness against emergency department visits, intensive care unit admissions, or death.

Why it matters

RSV-associated LRTI hospitalization is an important early-life outcome, and these real-world findings indicate that maternal RSVpreF vaccination is associated with substantial protection across the first 6 months. The results add postimplementation evidence beyond the pivotal trial and inform assessment of antenatal immunization programs, while evidence for other severe or acute-care outcomes remains limited.

What to keep in mind

The evidence came from only 7 nonrandomized studies, and limited data precluded meta-analysis of emergency department visits, intensive care unit admissions, and death.