To evaluate the effectiveness of the BNT162b2 messenger RNA vaccine in pregnant women, we conducted an observational cohort study of pregnant women aged 16 years or older, with no history of SARS-CoV-2, who were vaccinated between 20 December 2020 and 3 June 2021. A total of 10,861 vaccinated pregnant women were matched to 10,861 unvaccinated pregnant controls using demographic and clinical characteristics. Study outcomes included documented infection with SARS-CoV-2, symptomatic COVID-19, COVID-19-related hospitalization, severe illness and death. Estimated vaccine effectiveness from 7 through to 56 d after the second dose was 96% (95% confidence interval 89–100%) for any documented infection, 97% (91–100%) for infections with documented symptoms and 89% (43–100%) for COVID-19-related hospitalization. Only one event of severe illness was observed in the unvaccinated group and no deaths were observed in either group. In summary, the BNT162b2 mRNA vaccine was estimated to have high vaccine effectiveness in pregnant women, which is similar to the effectiveness estimated in the general population.

为了评估 BNT162b2 信使 RNA 疫苗在孕妇中的有效性，我们对 2020 年 12 月 20 日至 2021 年 6 月 3 日期间接种疫苗的 16 岁或以上且没有 SARS-CoV-2 病史的孕妇进行了一项观察性队列研究. 使用人口统计学和临床​​特征将总共 10,861 名接种疫苗的孕妇与 10,861 名未接种疫苗的孕妇对照进行匹配。研究结果包括记录的 SARS-CoV-2 感染、有症状的 COVID-19、与 COVID-19 相关的住院、严重疾病和死亡。第二剂后 7 至 56 天的疫苗有效性估计为 96%（95% 置信区间 89-100%），对于任何记录的感染，97%（91-100%）对于有记录症状的感染和 89%（43- 100%) 用于 COVID-19 相关的住院治疗。在未接种疫苗的组中仅观察到一次严重疾病事件，并且在任一组中均未观察到死亡。综上所述，估计 BNT162b2 mRNA 疫苗在孕妇中具有较高的疫苗有效性，这与在一般人群中估计的有效性相似。