Background

Waning of vaccine protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or coronavirus disease 2019 (Covid-19) is a concern. The persistence of BNT162b2 (Pfizer–BioNTech) vaccine effectiveness against infection and disease in Qatar, where the B.1.351 (or beta) and B.1.617.2 (or delta) variants have dominated incidence and polymerase-chain-reaction testing is done on a mass scale, is unclear.

Methods

We used a matched test-negative, case–control study design to estimate vaccine effectiveness against any SARS-CoV-2 infection and against any severe, critical, or fatal case of Covid-19, from January 1 to September 5, 2021.

Results

Estimated BNT162b2 effectiveness against any SARS-CoV-2 infection was negligible in the first 2 weeks after the first dose. It increased to 36.8% (95% confidence interval [CI], 33.2 to 40.2) in the third week after the first dose and reached its peak at 77.5% (95% CI, 76.4 to 78.6) in the first month after the second dose. Effectiveness declined gradually thereafter, with the decline accelerating after the fourth month to reach approximately 20% in months 5 through 7 after the second dose. Effectiveness against symptomatic infection was higher than effectiveness against asymptomatic infection but waned similarly. Variant-specific effectiveness waned in the same pattern. Effectiveness against any severe, critical, or fatal case of Covid-19 increased rapidly to 66.1% (95% CI, 56.8 to 73.5) by the third week after the first dose and reached 96% or higher in the first 2 months after the second dose; effectiveness persisted at approximately this level for 6 months.

Conclusions

BNT162b2-induced protection against SARS-COV-2 infection appeared to wane rapidly following its peak after the second dose, but protection against hospitalization and death persisted at a robust level for 6 months after the second dose. (Funded by Weill Cornell Medicine–Qatar and others.)

中文翻译：

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卡塔尔 BNT162b2 疫苗对 SARS-CoV-2 感染的保护作用减弱

背景

针对严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 感染或 2019 年冠状病毒病 (Covid-19) 的疫苗保护作用减弱令人担忧。BNT162b2（辉瑞-BioNTech）疫苗在卡塔尔对感染和疾病的持续有效性，其中 B.1.351（或 beta）和 B.1.617.2（或 delta）变种的发病率占主导地位，并进行了聚合酶链反应测试在大规模范围内，尚不清楚。

方法

我们使用匹配的测试阴性病例对照研究设计来评估2021年1月1日至9月5日期间疫苗针对任何SARS-CoV-2感染以及任何严重、危重或致命的Covid-19病例的有效性。

结果

估计 BNT162b2 对任何 SARS-CoV-2 感染的有效性在第一次给药后的前两周内可以忽略不计。第一次给药后第三周增加至 36.8%（95% 置信区间 [CI]，33.2 至 40.2），第二次给药后第一个月达到峰值 77.5%（95% CI，76.4 至 78.6） 。此后有效性逐渐下降，在第四个月后下降加速，在第二次给药后的第 5 至 7 个月达到约 20%。针对有症状感染的有效性高于针对无症状感染的有效性，但同样下降。特定变体的有效性以同样的方式减弱。在第一次注射后的第三周，针对任何严重、危重或致命的 Covid-19 病例的有效性迅速增加至 66.1%（95% CI，56.8 至 73.5），并在第二次注射后的前 2 个月内达到 96% 或更高剂量; 有效性在大约这个水平上持续了 6 个月。

结论

BNT162b2 诱导的针对 SARS-COV-2 感染的保护作用在第二次给药后达到峰值后似乎迅速减弱，但在第二次给药后 6 个月内，针对住院和死亡的保护作用持续保持在强劲水平。（由威尔康奈尔医学院卡塔尔等机构资助。）