BCG vaccine protection from severe coronavirus disease 2019 (COVID-19)
BCG vaccine protection from severe coronavirus disease 2019 (COVID-19)
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DOI：
10.1073/pnas.2008410117
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发表时间：
2020-07-28
影响因子：
11.1
通讯作者：
Barillas-Mury, Carolina
中科院分区：
文献类型：
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作者：
Escobar, Luis E.;Molina-Cruz, Alvaro;Barillas-Mury, Carolina
一系列流行病学调查表明，国家卡介苗接种政策与2019冠状病毒病（COVID-19）的患病率和死亡率呈负相关。然而，由于各国之间存在巨大差异，例如社会经济地位、人口结构、农村与城市环境、大流行到来的时间、诊断检测的数量和检测标准，以及限制COVID-19传播的国家控制战略，这些比较很难得到验证。我们回顾了卡介苗对严重COVID-19交叉保护的潜在生物学基础的证据，并完善了流行病学分析，以减轻潜在的混杂因素（如COVID-19流行阶段、发展、农村、人口密度和年龄结构）的影响。在社会相似的不同欧洲国家，卡介苗指数（估计一个国家普遍接种卡介苗的程度）与COVID-19死亡率之间存在很强的相关性(r(2) = 0.88；P = 8 × 10(-7))，表明卡介苗指数每增加10%与COVID-19死亡率降低10.4%相关。结果未能证实卡介苗接种与COVID-19死亡率无关联的原假设，提示卡介苗可能具有保护作用。然而，分析仅限于粗尺度信号，应谨慎考虑。需要进行卡介苗接种临床试验来证实这里发现的模式，并确定卡介苗接种与预防严重COVID-19之间的因果关系。讨论了卡介苗交叉保护对严重COVID-19的公共卫生影响。
A series of epidemiological explorations has suggested a negative association between national bacillus Calmette-Guerin (BCG) vac-cination policy and the prevalence and mortality of coronavirus disease 2019 (COVID-19). However, these comparisons are difficult to validate due to broad differences between countries such as socioeconomic status, demographic structure, rural vs. urban set-tings, time of arrival of the pandemic, number of diagnostic tests and criteria for testing, and national control strategies to limit the spread of COVID-19. We review evidence for a potential biological basis of BCG cross-protection from severe COVID-19, and refine the epidemiological analysis to mitigate effects of potentially con-founding factors (e.g., stage of the COVID-19 epidemic, develop-ment, rurality, population density, and age structure). A strong correlation between the BCG index, an estimation of the degree of universal BCG vaccination deployment in a country, and COVID-19 mortality in different socially similar European countries was observed (r(2) = 0.88; P = 8 x 10(-7)), indicating that every 10% in-crease in the BCG index was associated with a 10.4% reduction in COVID-19 mortality. Results fail to confirm the null hypothesis of no association between BCG vaccination and COVID-19 mortality, and suggest that BCG could have a protective effect. Nevertheless, the analyses are restricted to coarse-scale signals and should be considered with caution. BCG vaccination clinical trials are required to corroborate the patterns detected here, and to establish causal-ity between BCG vaccination and protection from severe COVID-19. Public health implications of a plausible BCG cross-protection from severe COVID-19 are discussed.