Instituto Gonçalo Moniz, Fiocruz, Salvador, BA, Brazil; Faculdade de Medicina, Universidade Federal da Bahia, Salvador, BA, Brazil.
Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA.
Lancet Infect Dis. 2022 Jun;22(6):791-801. doi: 10.1016/S1473-3099(22)00140-2. Epub 2022 Apr 1.
COVID-19 vaccines have proven highly effective among individuals without a previous SARS-CoV-2 infection, but their effectiveness in preventing symptomatic infection and severe outcomes among individuals with previous infection is less clear. We aimed to estimate the effectiveness of four COVID-19 vaccines against symptomatic infection, hospitalisation, and death for individuals with laboratory-confirmed previous SARS-CoV-2 infection.
Using national COVID-19 notification, hospitalisation, and vaccination datasets from Brazil, we did a test-negative, case-control study to assess the effectiveness of four vaccines (CoronaVac [Sinovac], ChAdOx1 nCoV-19 [AstraZeneca], Ad26.COV2.S [Janssen], and BNT162b2 [Pfizer-BioNtech]) for individuals with laboratory-confirmed previous SARS-CoV-2 infection. We matched cases with RT-PCR positive, symptomatic COVID-19 with up to ten controls with negative RT-PCR tests who presented with symptomatic illnesses, restricting both groups to tests done at least 90 days after an initial infection. We used multivariable conditional logistic regression to compare the odds of test positivity and the odds of hospitalisation or death due to COVID-19, according to vaccination status and time since first or second dose of vaccines.
Between Feb 24, 2020, and Nov 11, 2021, we identified 213 457 individuals who had a subsequent, symptomatic illness with RT-PCR testing done at least 90 days after their initial SARS-CoV-2 infection and after the vaccination programme started. Among these, 30 910 (14·5%) had a positive RT-PCR test consistent with reinfection, and we matched 22 566 of these cases with 145 055 negative RT-PCR tests from 68 426 individuals as controls. Among individuals with previous SARS-CoV-2 infection, vaccine effectiveness against symptomatic infection 14 or more days from vaccine series completion was 39·4% (95% CI 36·1-42·6) for CoronaVac, 56·0% (51·4-60·2) for ChAdOx1 nCoV-19, 44·0% (31·5-54·2) for Ad26.COV2.S, and 64·8% (54·9-72·4) for BNT162b2. For the two-dose vaccine series (CoronaVac, ChAdOx1 nCoV-19, and BNT162b2), effectiveness against symptomatic infection was significantly greater after the second dose than after the first dose. Effectiveness against hospitalisation or death 14 or more days from vaccine series completion was 81·3% (75·3-85·8) for CoronaVac, 89·9% (83·5-93·8) for ChAdOx1 nCoV-19, 57·7% (-2·6 to 82·5) for Ad26.COV2.S, and 89·7% (54·3-97·7) for BNT162b2.
All four vaccines conferred additional protection against symptomatic infections and severe outcomes among individuals with previous SARS-CoV-2 infection. The provision of a full vaccine series to individuals after recovery from COVID-19 might reduce morbidity and mortality.
Brazilian National Research Council, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Oswaldo Cruz Foundation, JBS, Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation, and Generalitat de Catalunya.
COVID-19 疫苗在未感染 SARS-CoV-2 的个体中表现出高度有效性，但在既往感染个体中预防有症状感染和严重结局的有效性尚不明确。我们旨在评估四种 COVID-19 疫苗对既往 SARS-CoV-2 感染个体的有症状感染、住院和死亡的有效性。
使用来自巴西的 COVID-19 报告、住院和疫苗接种数据集，我们进行了一项阴性对照病例对照研究，以评估四种疫苗（科兴（Sinovac）的 CoronaVac、阿斯利康（AstraZeneca）的 ChAdOx1 nCoV-19、杨森（Janssen）的 Ad26.COV2.S 和辉瑞-生物科技（Pfizer-BioNtech）的 BNT162b2）对既往 SARS-CoV-2 感染个体的有效性。我们将 RT-PCR 阳性、有症状 COVID-19 的病例与 RT-PCR 阴性、有症状疾病的最多 10 名对照相匹配，限制两组均在首次感染后至少 90 天进行测试。我们使用多变量条件逻辑回归来比较根据疫苗接种状况和首次或第二剂疫苗接种后时间，疫苗接种阳性的可能性和因 COVID-19 住院或死亡的可能性。
在 2020 年 2 月 24 日至 2021 年 11 月 11 日期间，我们确定了 213457 名随后有症状疾病且 RT-PCR 检测在首次 SARS-CoV-2 感染后至少 90 天和疫苗接种计划开始后进行的个体。其中，30910 人（14.5%）的 RT-PCR 检测结果呈阳性，与再感染一致，我们从 68426 名个体中匹配了 22566 名这些病例与 145055 名 RT-PCR 阴性检测作为对照。在既往 SARS-CoV-2 感染个体中，疫苗系列完成后 14 天或以上对有症状感染的疫苗有效性为 CoronaVac 39.4%（95%CI 36.1-42.6），ChAdOx1 nCoV-19 56.0%（51.4-60.2），Ad26.COV2.S 44.0%（31.5-54.2）和 BNT162b2 64.8%（54.9-72.4）。对于两剂疫苗系列（CoronaVac、ChAdOx1 nCoV-19 和 BNT162b2），第二剂后的有效性明显大于第一剂。疫苗系列完成后 14 天或以上对住院或死亡的有效性为 CoronaVac 81.3%（75.3-85.8），ChAdOx1 nCoV-19 89.9%（83.5-93.8），Ad26.COV2.S 57.7%（-2.6 至 82.5）和 BNT162b2 89.7%（54.3-97.7）。
四种疫苗都为既往 SARS-CoV-2 感染个体提供了针对有症状感染和严重结局的额外保护。在 COVID-19 康复后为个体提供完整的疫苗接种系列可能会降低发病率和死亡率。
巴西国家研究理事会、里约热内卢州卡洛斯·查加斯研究支持基金会、卡洛斯三世健康研究所、西班牙科学创新部、加泰罗尼亚政府。
