Objective To estimate the real world effectiveness of the Pfizer-BioNTech BNT162b2 and Oxford-AstraZeneca ChAdOx1-S vaccines against confirmed covid-19 symptoms (including the UK variant of concern B.1.1.7), admissions to hospital, and deaths. Design Test negative case-control study. Setting Community testing for covid-19 in England. Participants 156 930 adults aged 70 years and older who reported symptoms of covid-19 between 8 December 2020 and 19 February 2021 and were successfully linked to vaccination data in the National Immunisation Management System. Interventions Vaccination with BNT162b2 or ChAdOx1-S. Main outcome measures Primary outcomes were polymerase chain reaction confirmed symptomatic SARS-CoV-2 infections, admissions to hospital for covid-19, and deaths with covid-19. Results Participants aged 80 years and older vaccinated with BNT162b2 before 4 January 2021 had a higher odds of testing positive for covid-19 in the first nine days after vaccination (odds ratio up to 1.48, 95% confidence interval 1.23 to 1.77), indicating that those initially targeted had a higher underlying risk of infection. Vaccine effectiveness was therefore compared with the baseline post-vaccination period. Vaccine effects were noted 10 to 13 days after vaccination, reaching a vaccine effectiveness of 70% (95% confidence interval 59% to 78%), then plateauing. From 14 days after the second dose a vaccination effectiveness of 89% (85% to 93%) was found compared with the increased baseline risk. Participants aged 70 years and older vaccinated from 4 January (when ChAdOx1-S delivery commenced) had a similar underlying risk of covid-19 to unvaccinated individuals. With BNT162b2, vaccine effectiveness reached 61% (51% to 69%) from 28 to 34 days after vaccination, then plateaued. With ChAdOx1-S, effects were seen from 14 to 20 days after vaccination, reaching an effectiveness of 60% (41% to 73%) from 28 to 34 days, increasing to 73% (27% to 90%) from day 35 onwards. On top of the protection against symptomatic disease, a further 43% (33% to 52%) reduced risk of emergency hospital admission and 51% (37% to 62%) reduced risk of death was observed in those who had received one dose of BNT162b2. Participants who had received one dose of ChAdOx1-S had a further 37% (3% to 59%) reduced risk of emergency hospital admission. Follow-up was insufficient to assess the effect of ChAdOx1-S on mortality. Combined with the effect against symptomatic disease, a single dose of either vaccine was about 80% effective at preventing admission to hospital with covid-19 and a single dose of BNT162b2 was 85% effective at preventing death with covid-19. Conclusion Vaccination with either one dose of BNT162b2 or ChAdOx1-S was associated with a significant reduction in symptomatic covid-19 in older adults, and with further protection against severe disease. Both vaccines showed similar effects. Protection was maintained for the duration of follow-up (>6 weeks). A second dose of BNT162b2 was associated with further protection against symptomatic disease. A clear effect of the vaccines against the B.1.1.7 variant was found.

中文翻译：

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Pfizer-BioNTech 和 Oxford-AstraZeneca 疫苗对英格兰老年人 covid-19 相关症状、住院和死亡率的有效性：测试阴性病例对照研究

目的 评估 Pfizer-BioNTech BNT162b2 和 Oxford-AstraZeneca ChAdOx1-S 疫苗针对确诊的 covid-19 症状（包括英国关注的 B.1.1.7 变体）、入院和死亡的真实世界有效性。设计测试阴性病例对照研究。在英格兰为 covid-19 设置社区测试。参与者 156 930 名 70 岁及以上的成年人，他们在 2020 年 12 月 8 日至 2021 年 2 月 19 日期间报告了 covid-19 的症状，并成功地与国家免疫管理系统中的疫苗接种数据相关联。使用 BNT162b2 或 ChAdOx1-S 进行干预接种。主要结局指标主要结局是聚合酶链反应证实有症状的 SARS-CoV-2 感染、因 covid-19 入院以及因 covid-19 而死亡。结果 在 2021 年 1 月 4 日之前接种 BNT162b2 的 80 岁及以上参与者在接种疫苗后的前 9 天内检测出 covid-19 呈阳性的几率更高（优势比高达 1.48，95% 置信区间为 1.23 至 1.77），表明那些最初成为目标的人有更高的潜在感染风险。因此，将疫苗有效性与疫苗接种后的基线期进行了比较。疫苗接种后 10 至 13 天观察到疫苗效果，达到 70% 的疫苗有效性（95% 置信区间 59% 至 78%），然后趋于稳定。从第二次接种后 14 天开始，与增加的基线风险相比，发现疫苗接种的有效性为 89%（85% 至 93%）。从 1 月 4 日（ChAdOx1-S 开始递送时）开始接种疫苗的 70 岁及以上参与者与未接种疫苗的个体具有相似的潜在 COVID-19 风险。使用 BNT162b2，疫苗接种后 28 至 34 天，疫苗有效性达到 61%（51% 至 69%），然后趋于稳定。使用 ChAdOx1-S，在接种后 14 至 20 天观察到效果，从 28 至 34 天达到 60%（41% 至 73%）的有效率，从第 35 天起增加至 73%（27% 至 90%） . 除了预防有症状的疾病外，在接受一剂注射剂治疗的患者中观察到，急诊入院风险进一步降低 43%（33% 至 52%），死亡风险降低 51%（37% 至 62%）。 BNT162b2。接受一剂 ChAdOx1-S 的参与者紧急住院的风险进一步降低了 37%（3% 至 59%）。随访不足以评估 ChAdOx1-S 对死亡率的影响。结合对有症状的疾病的作用，单剂量的任一疫苗在预防因 covid-19 入院方面的有效性约为 80%，而单剂量的 BNT162b2 在预防因 covid-19 导致的死亡方面的有效性为 85%。结论 接种一剂 BNT162b2 或 ChAdOx1-S 可显着减少老年人的症状性 COVID-19，并进一步预防严重疾病。两种疫苗都显示出相似的效果。在随访期间（>6 周）保持保护。第二剂 BNT162b2 与对症状性疾病的进一步保护有关。发现疫苗对 B.1.1.7 变体的明显效果。结合对有症状的疾病的作用，单剂量的任一疫苗在预防因 covid-19 入院方面的有效性约为 80%，而单剂量的 BNT162b2 在预防因 covid-19 导致的死亡方面的有效性为 85%。结论 接种一剂 BNT162b2 或 ChAdOx1-S 可显着减少老年人的症状性 COVID-19，并进一步预防严重疾病。两种疫苗都显示出相似的效果。在随访期间（>6 周）保持保护。第二剂 BNT162b2 与对症状性疾病的进一步保护有关。发现疫苗对 B.1.1.7 变体的明显效果。结合对有症状的疾病的作用，单剂量的任一疫苗在预防因 covid-19 入院方面的有效性约为 80%，而单剂量的 BNT162b2 在预防因 covid-19 导致的死亡方面的有效性为 85%。结论 接种一剂 BNT162b2 或 ChAdOx1-S 可显着减少老年人的症状性 COVID-19，并进一步预防严重疾病。两种疫苗都显示出相似的效果。在随访期间（>6 周）保持保护。第二剂 BNT162b2 与对症状性疾病的进一步保护有关。发现疫苗对 B.1.1.7 变体的明显效果。单剂量的任一疫苗在预防因 covid-19 入院方面的有效性约为 80%，单剂量的 BNT162b2 在预防因 covid-19 导致的死亡方面的有效性为 85%。结论 接种一剂 BNT162b2 或 ChAdOx1-S 可显着减少老年人的症状性 COVID-19，并进一步预防严重疾病。两种疫苗都显示出相似的效果。在随访期间（>6 周）保持保护。第二剂 BNT162b2 与对症状性疾病的进一步保护有关。发现疫苗对 B.1.1.7 变体的明显效果。单剂量的任一疫苗在预防因 covid-19 入院方面的有效性约为 80%，单剂量的 BNT162b2 在预防因 covid-19 导致的死亡方面的有效性为 85%。结论 接种一剂 BNT162b2 或 ChAdOx1-S 可显着减少老年人的症状性 COVID-19，并进一步预防严重疾病。两种疫苗都显示出相似的效果。在随访期间（>6 周）保持保护。第二剂 BNT162b2 与对症状性疾病的进一步保护有关。发现疫苗对 B.1.1.7 变体的明显效果。结论 接种一剂 BNT162b2 或 ChAdOx1-S 可显着减少老年人的症状性 COVID-19，并进一步预防严重疾病。两种疫苗都显示出相似的效果。在随访期间（>6 周）保持保护。第二剂 BNT162b2 与对症状性疾病的进一步保护有关。发现疫苗对 B.1.1.7 变体的明显效果。结论 接种一剂 BNT162b2 或 ChAdOx1-S 可显着减少老年人的症状性 COVID-19，并进一步预防严重疾病。两种疫苗都显示出相似的效果。在随访期间（>6 周）保持保护。第二剂 BNT162b2 与对症状性疾病的进一步保护有关。发现疫苗对 B.1.1.7 变体的明显效果。