RSV vaccine in pregnancy vs baby's antibody shot

How do the options compare?

Options are stacked on five dimensions relevant to pregnancy use: mainstream OB guidance, pregnancy-specific evidence, dosing predictability, onset, and side-effect and interaction profile.

• Abrysvo is approved for administration to pregnant women at 32 to 36 weeks of gestation, with efficacy of 81.8% within 90 days of birth and 69.4% within 180 days. 1
• FDA narrowed the dosing interval from the 24 to 36 weeks originally studied down to 32 through 36 weeks, because preterm births ran 5.7% among vaccine recipients against 4.7% on placebo across the full window, while the imbalance in the restricted subgroup was 0.5%. 2
• In the 32 to 36 week subgroup, vaccine efficacy against severe RSV lower respiratory tract disease in infants was 76.5% within 180 days after birth, covering roughly the first six months of life. 2
• Nirsevimab is a human IgG1 kappa monoclonal antibody given as a single intramuscular injection, dosed 50 mg under 5 kg and 100 mg at 5 kg or more in the first season, starting from birth for babies born during the season and once before the season for babies born outside it. 3
• A single nirsevimab injection provides protection for a minimum of five months and showed 90.5% real-world effectiveness at reducing RSV-related hospitalisations, and it is directed at infants born to parents who did not receive the maternal vaccine or who have high-risk conditions. 4

Which option makes sense?

Options in this comparison can differ substantially in suitability. Please consult your healthcare provider to interpret the evidence, limitations, and cautions before choosing an option or changing your plan.

Disclosure: Pregnancy Smart makes supplements in this category. The comparison above is written to inform, not to steer readers toward or away from our brand.