Department of Health Policy and Management, Institute of Health, Jimma University, Jimma, Ethiopia.
Department of Health Policy and Management, Institute of Health, Jimma University, Jimma, Ethiopia; Ethiopian Evidence Based Health Care Centre, Health, Behaviour, and Society Department, Public Health Faculty, Jimma Institute of Health Sciences, Jimma University, Ethiopia.
Vaccine. 2020 Sep 22;38(41):6374-6380. doi: 10.1016/j.vaccine.2020.08.018. Epub 2020 Aug 10.
The rapid spread of the Coronavirus pandemic and its significant health and social impact urges the search for effective and readily available solutions to mitigate the damages. Thus, evaluating the effectiveness of existing vaccines like Bacillus Calmette-Guérin (BCG) has attracted attention. The aim of this review was evidence synthesis on the effect of BCG vaccine in preventing severe infectious respiratory disease including COVD-19, but not tuberculosis. We considered studies conducted on human participants of any study design from any country setting that were published in Enlgish. We did a systematic literature search in MEDLINE, Scopus and Google scholar databases and a free search on Google. The identified studies were appraised and relevant data were extracted using Joanna Briggs Institute tools. The extracted findings were synthesized with tables and narrative summary. Nine studies met the inclusion criteria. The findings indicated that BCG vaccine has a strong protective effect against both upper and lower acute respiratory tract infections. For instance in countries with universal BCG vaccination policy, the incidence of COVID-19 was lower compared to the counterparts. Addtionally, BCG vaccine was found to protect against infections like lethal influenza A virus, pandemic influenza (H1N1), and other acute respiratory tract infections. BCG improved the human body's immune response involving antigen-specific T cells and memory cells. It also induced adaptive functional reprogramming of mononuclear phagocytes that induce protective effects against different respiratory infections other than tuberculosis. In countries with universal BCG vaccination, the incidence and death from acute respiratory viral infection including COVID - 19 is significantly low. However, there is an urgent need for further evidence from well-designed studies to understand the possible role of BCG vaccination over time and across age groups, its possible benefits in special populations such as health workers and cost-savings related to a policy of universal BCG vaccination.
冠状病毒大流行的迅速传播及其对健康和社会的重大影响，促使人们寻找有效且易于获得的解决方案来减轻其危害。因此，评估卡介苗（BCG）等现有疫苗的有效性引起了关注。本综述的目的是综合评估卡介苗疫苗在预防严重传染性呼吸道疾病（包括 COVID-19 但不包括结核病）方面的效果。我们考虑了任何国家背景下任何研究设计的人类参与者的研究，且这些研究必须发表在英文期刊上。我们在 MEDLINE、Scopus 和 Google Scholar 数据库中进行了系统的文献检索，并在 Google 上进行了免费搜索。对确定的研究进行评估，并使用 Joanna Briggs 研究所的工具提取相关数据。使用表格和叙述性摘要对提取的发现进行综合。有 9 项研究符合纳入标准。研究结果表明，卡介苗疫苗对上下呼吸道急性感染均具有强大的保护作用。例如，在普遍实行卡介苗接种政策的国家，COVID-19 的发病率低于没有实行该政策的国家。此外，卡介苗疫苗被发现可预防致命性流感 A 病毒、大流行性流感（H1N1）和其他急性呼吸道感染。卡介苗可改善人体的免疫反应，包括抗原特异性 T 细胞和记忆细胞。它还诱导单核吞噬细胞的适应性功能重编程，从而对除结核病以外的不同呼吸道感染产生保护作用。在普遍实行卡介苗接种的国家，急性呼吸道病毒感染（包括 COVID-19）的发病率和死亡率显著降低。然而，迫切需要进一步的证据来自精心设计的研究，以了解卡介苗接种随着时间的推移和在不同年龄组中的可能作用、它在卫生工作者等特殊人群中的可能益处以及普遍实行卡介苗接种政策的成本节约。
