Table 1 Vaccine effectiveness measures

From: Effectiveness of the BNT162b2 mRNA COVID-19 vaccine in pregnancy

Period Documented infection Symptomatic infection Hospitalization Severe disease
  1 − RR (95% CI) RD (95% CI) 1 − RR (95% CI) RD (95% CI) 1 − RR (95% CI) RD (95% CI) 1 − RR (95% CI) RD (95% CI)
Days 14–20 after first dose 67% (40–84%) 309.22 (145.43–485.69) 66% (32–86%) 223.59 (82.44–361.63) 3 versus 0a 2 versus 0a
Days 21–27 after first dose 71% (33–94%) 157.30 (41.42–285.23) 76% (30–100%) 116.52 (26.92–217.92) 5 versus 0a 0 versus 0a
Days 7–56 after second dose 96% (89–100%) 933.40 (685.60–1192.33) 97% (91–100%) 621.70 (433.68–847.26) 89% (43–100%) 132.28 (31.67–241.03) 1 versus 0a
  1. RRs and RDs (per 100,000 persons) of COVID-19 outcomes for vaccination versus no vaccination at several time points after vaccination in pregnant women who are members of the CHS, 20 December 2020 through to 3 June 2021. The study population numbered 10,861 individuals in each arm and 1,529 individuals were first included as unvaccinated and then re-recruited as vaccinated.
  2. aEstimates were only calculated for cells with more than five events; otherwise, raw counts are reported.