BCG Vaccination: A potential tool against COVID-19 and COVID-19-like Black Swan incidents.
Int Immunopharmacol 2022;
108:108870. [PMID:
35597119 PMCID:
PMC9113676 DOI:
10.1016/j.intimp.2022.108870]
[Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/07/2022] [Accepted: 05/12/2022] [Indexed: 12/17/2022]
Abstract
The severe acute respiratory syndrome
coronavirus 2 (SARS-CoV-2), the causative agent of the coronavirus
disease 2019 (COVID-19), and its variants have brought unprecedented
impacts to the global public health system, politics, economy, and other
fields. Although more than ten COVID-19 specific vaccines have been
approved for emergency use, COVID-19 prevention and control still face
many challenges. Bacille Calmette–Guérin (BCG) is the only authorized
vaccine used to fight against tuberculosis (TB), it has been hypothesized
that BCG may prevent and control COVID-19 based on BCG-induced
nonspecific immune responses. Herein, we summarized: 1) The nonspecific
protection effects of BCG, such as prophylactic protection effects of BCG
on nonmycobacterial infections, immunotherapy effects of BCG vaccine, and
enhancement effect of BCG vaccine on unrelated vaccines; 2) Recent
evidence of BCG's efficacy against SARS-COV-2 infection from ecological
studies, analytical analyses, clinical trials, and animal studies; 3)
Three possible mechanisms of BCG vaccine and their effects on COVID-19
control including heterologous immunity, trained immunity, and
anti-inflammatory effect. We hope that this review will encourage more
scientists to investigate further BCG induced non-specific immune
responses and explore their mechanisms, which could be a potential tool
for addressing the COVID-19 pandemic and COVID-19-like “Black Swan”
events to reduce the impacts of infectious disease outbreaks on public
health, politics, and economy.
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