Abstract：
BACKGROUND: Vaccines were developed and deployed to combat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aimed to characterize patterns in the protection provided by the BNT162b2 and mRNA-1273 mRNA vaccines against a spectrum of SARS-CoV-2 infection symptoms and severities.
METHODS: A national, matched, test-negative, case-control study was conducted in Qatar between January 1 and December 18, 2021, utilizing a sample of 238,896 PCR-positive tests and 6,533,739 PCR-negative tests. Vaccine effectiveness was estimated against asymptomatic, symptomatic, severe coronavirus disease 2019 (COVID-19), critical COVID-19, and fatal COVID-19 infections. Data sources included Qatar\'s national databases for COVID-19 laboratory testing, vaccination, hospitalization, and death.
RESULTS: Effectiveness of two-dose BNT162b2 vaccination was 75.6% (95% CI: 73.6-77.5) against asymptomatic infection and 76.5% (95% CI: 75.1-77.9) against symptomatic infection. Effectiveness against each of severe, critical, and fatal COVID-19 infections surpassed 90%. Immediately after the second dose, all categories-namely, asymptomatic, symptomatic, severe, critical, and fatal COVID-19-exhibited similarly high effectiveness. However, from 181 to 270 days post-second dose, effectiveness against asymptomatic and symptomatic infections declined to below 40%, while effectiveness against each of severe, critical, and fatal COVID-19 infections remained consistently high. However, estimates against fatal COVID-19 often had wide 95% confidence intervals. Analogous patterns were observed in three-dose BNT162b2 vaccination and two- and three-dose mRNA-1273 vaccination. Sensitivity analyses confirmed the results.
CONCLUSIONS: A gradient in vaccine effectiveness exists and is linked to the symptoms and severity of infection, providing higher protection against more symptomatic and severe cases. This gradient intensifies over time as vaccine immunity wanes after the last vaccine dose. These patterns appear consistent irrespective of the vaccine type or whether the vaccination involves the primary series or a booster.
METHODS: A national, matched, test-negative, case-control study was conducted in Qatar between January 1 and December 18, 2021, utilizing a sample of 238,896 PCR-positive tests and 6,533,739 PCR-negative tests. Vaccine effectiveness was estimated against asymptomatic, symptomatic, severe coronavirus disease 2019 (COVID-19), critical COVID-19, and fatal COVID-19 infections. Data sources included Qatar\'s national databases for COVID-19 laboratory testing, vaccination, hospitalization, and death.
RESULTS: Effectiveness of two-dose BNT162b2 vaccination was 75.6% (95% CI: 73.6-77.5) against asymptomatic infection and 76.5% (95% CI: 75.1-77.9) against symptomatic infection. Effectiveness against each of severe, critical, and fatal COVID-19 infections surpassed 90%. Immediately after the second dose, all categories-namely, asymptomatic, symptomatic, severe, critical, and fatal COVID-19-exhibited similarly high effectiveness. However, from 181 to 270 days post-second dose, effectiveness against asymptomatic and symptomatic infections declined to below 40%, while effectiveness against each of severe, critical, and fatal COVID-19 infections remained consistently high. However, estimates against fatal COVID-19 often had wide 95% confidence intervals. Analogous patterns were observed in three-dose BNT162b2 vaccination and two- and three-dose mRNA-1273 vaccination. Sensitivity analyses confirmed the results.
CONCLUSIONS: A gradient in vaccine effectiveness exists and is linked to the symptoms and severity of infection, providing higher protection against more symptomatic and severe cases. This gradient intensifies over time as vaccine immunity wanes after the last vaccine dose. These patterns appear consistent irrespective of the vaccine type or whether the vaccination involves the primary series or a booster.
摘要：
背景：开发并部署了疫苗来对抗严重急性呼吸道综合征冠状病毒2（SARS-CoV-2）感染。这项研究旨在表征BNT162b2和mRNA-1273mRNA疫苗提供的针对SARS-CoV-2感染症状和严重程度的保护模式。
方法：国家，匹配，检测阴性,病例对照研究于2021年1月1日至12月18日在卡塔尔进行,样本为238,896个PCR阳性检测和6,533,739个PCR阴性检测.疫苗有效性是根据无症状估计的，症状,2019年严重冠状病毒病（COVID-19），严重的COVID-19和致命的COVID-19感染。数据来源包括卡塔尔国家COVID-19实验室检测数据库，疫苗接种,住院治疗,和死亡。
结果：两剂BNT162b2疫苗对无症状感染的有效性为75.6％（95％CI：73.6-77.5），对有症状感染的有效性为76.5％（95％CI：75.1-77.9）。对每一个严重的有效性，关键,致命的COVID-19感染超过90%。第二次给药后，所有类别-即，无症状，症状,严重,关键,和致命的COVID-19表现出类似的高疗效。然而,从181到270天第二次剂量后，对无症状和有症状感染的有效性下降到40%以下，虽然对每一个严重的有效性，关键,致命的COVID-19感染仍然很高。然而,对致命COVID-19的估计通常有95%的置信区间。在三剂量BNT162b2疫苗接种和二剂量和三剂量mRNA-1273疫苗接种中观察到类似的模式。敏感性分析证实了结果。
结论：疫苗有效性存在梯度，并且与感染的症状和严重程度有关。提供更高的保护，防止更多的症状和严重的病例。随着疫苗免疫力在最后一次疫苗剂量后减弱，这种梯度会随着时间的推移而加剧。无论疫苗类型或疫苗接种是否涉及主要系列或加强剂，这些模式看起来都是一致的。
方法：国家，匹配，检测阴性,病例对照研究于2021年1月1日至12月18日在卡塔尔进行,样本为238,896个PCR阳性检测和6,533,739个PCR阴性检测.疫苗有效性是根据无症状估计的，症状,2019年严重冠状病毒病（COVID-19），严重的COVID-19和致命的COVID-19感染。数据来源包括卡塔尔国家COVID-19实验室检测数据库，疫苗接种,住院治疗,和死亡。
结果：两剂BNT162b2疫苗对无症状感染的有效性为75.6％（95％CI：73.6-77.5），对有症状感染的有效性为76.5％（95％CI：75.1-77.9）。对每一个严重的有效性，关键,致命的COVID-19感染超过90%。第二次给药后，所有类别-即，无症状，症状,严重,关键,和致命的COVID-19表现出类似的高疗效。然而,从181到270天第二次剂量后，对无症状和有症状感染的有效性下降到40%以下，虽然对每一个严重的有效性，关键,致命的COVID-19感染仍然很高。然而,对致命COVID-19的估计通常有95%的置信区间。在三剂量BNT162b2疫苗接种和二剂量和三剂量mRNA-1273疫苗接种中观察到类似的模式。敏感性分析证实了结果。
结论：疫苗有效性存在梯度，并且与感染的症状和严重程度有关。提供更高的保护，防止更多的症状和严重的病例。随着疫苗免疫力在最后一次疫苗剂量后减弱，这种梯度会随着时间的推移而加剧。无论疫苗类型或疫苗接种是否涉及主要系列或加强剂，这些模式看起来都是一致的。
