Maternal COVID-19 vaccination protects infants.

Researchers from the US Centers for Disease Control used a case–control design to ascertain if maternal COVID‐19 vaccination protects their infants against COVID‐19. They estimated vaccine effectiveness by comparing the odds of full maternal vaccination (two doses of mRNA vaccine) among 537 case infants <6 m hospitalised for COVID‐19 (181 during circulation of the B.1.617.2 (delta) and 356 during circulation of the B.1.1.259 (omicron) variant), and 512 control infants. The proportion of infants born to mothers who had been fully vaccinated against COVID‐19 during pregnancy was 16% of case infants and 29% of control infants. Among case infants, 113 (21%) received intensive care, including 64 (12%) who received mechanical ventilation or vasoactive infusions. Two case infants died from COVID‐19, neither of whose mother had been vaccinated during pregnancy. Maternal vaccination against hospitalisation for COVID‐19 among infants was 52% (95% confidence interval (CI), 33–65%): 80% (95% CI, 60–90%) during the delta period, and 38% (95% CI, 8–58%) during the omicron period. Vaccine effectiveness was 69% (95% CI, 50–80) when maternal vaccination occurred after 20 weeks gestation and 38% (95% CI, 3–60) during the first 20 weeks. Maternal COVID‐19 vaccination is safe and protects infants.