{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,19]],"date-time":"2026-06-19T14:54:37Z","timestamp":1781880877052,"version":"3.54.5"},"reference-count":103,"publisher":"IMR Press","issue":"5","license":[{"start":{"date-parts":[[2022,5,13]],"date-time":"2022-05-13T00:00:00Z","timestamp":1652400000000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Front. Biosci. (Landmark Ed)"],"abstract":"<jats:p>Coronavirus disease 2019 (COVID-19), which broke out at the end of 2019, is a global pandemic and seriously threatens human health. Vaccination is the most effective way to prevent and control COVID-19. At present, more than 13 COVID-19 vaccines have been urgently authorized for use, but the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has brought unprecedented challenges to the protective efficiency of these COVID-19 vaccines. In particular, the recent emergence of Delta and Omicron variants, which are rapidly spreading worldwide, may bring many challenges to the medical systems. Interestingly, previous studies have shown that the Bacillus Calmette-Guerin (BCG) vaccine used to prevent tuberculosis can induce non-specific trained immunity, protecting against infectious diseases caused by respiratory viruses. Therefore, there is a hypothesis that BCG plays an essential role in reducing the incidence, severity, hospitalization, and mortality of COVID-19 and enhancing the protection efficiency of the COVID-19 vaccine. To confirm this hypothesis, 56 clinical trials have been conducted globally to assess BCG\u2019s protective effectiveness against COVID-19 infection. Herein, this review discussed the trained immunity induced by BCG and its underlying mechanisms and summarised BCG\u2019s latest research progress in preventing COVID-19, especially the ongoing clinical trials. We hope this review will provide new strategies for fighting against COVID-19.<\/jats:p>","DOI":"10.31083\/j.fbl2705157","type":"journal-article","created":{"date-parts":[[2022,5,20]],"date-time":"2022-05-20T09:37:40Z","timestamp":1653039460000},"source":"Crossref","is-referenced-by-count":13,"title":["The Potential Roles of BCG Vaccine in the Prevention or Treatment of COVID-19"],"prefix":"10.31083","volume":"27","author":[{"given":"Jie","family":"Wang","sequence":"first","affiliation":[{"name":"Tuberculosis Prevention and Control Key Laboratory\/Beijing Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Senior Department of Tuberculosis, The 8th Medical Center of PLA General Hospital, 100091 Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qian","family":"Zhang","sequence":"first","affiliation":[{"name":"Department of General Medicine, The 8th Medical Center of PLA General Hospital, 100091 Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hongmei","family":"Wang","sequence":"first","affiliation":[{"name":"Department of General Medicine, The 8th Medical Center of PLA General Hospital, 100091 Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wenping","family":"Gong","sequence":"first","affiliation":[{"name":"Tuberculosis Prevention and Control Key Laboratory\/Beijing Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Senior Department of Tuberculosis, The 8th Medical Center of PLA General Hospital, 100091 Beijing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"16242","published-online":{"date-parts":[[2022,5,13]]},"reference":[{"key":"ref1","doi-asserted-by":"crossref","unstructured":"Doroftei B, Ciobica A, Ilie OD, Maftei R, Ilea C. 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