Convergence between global BCG vaccination and COVID‐19 pandemic

Abstract

The novel coronavirus SARS‐CoV‐2 has kept the whole world in tenterhooks due to its severe life‐threatening infectious disease, COVID‐19. The virus is distinct its cousins, SARS‐CoV and MERS‐CoV in term of severity of the infection. The obligated killing properties of the SARS‐CoV‐2 virus is mediated by its unique structure. Efforts for developing vaccines for COVID‐19 are ongoing, but it is unlikely to be available in the immediate future. Due to the absence of precise treatment, the investigators are discovering other effective, protective and healing choices. However, the lower than predictable number of SARS‐CoV‐2 cases in countries with fragile health systems is mystifying. Recently, there has been a buzz about the protective effect of BCG vaccine in COVID‐19 through long‐term boosting of trained immunity. Based on epidemiological correlations, we link up that BCG vaccination adopted by different countries might influence the SARS‐CoV‐2 transmission patterns and/or COVID‐19 associated mortality through the vaccine's capacity to confer heterologous protection. A number of clinical studies are underway to investigate this possibility but ‐even if they prove effective‐many questions will remain. Moreover, responsible stewardship of the BCG vaccine in the context of the COVID‐19 epidemic is directly needed. This article is protected by copyright. All rights reserved.

BCG Vaccination: A potential tool against COVID-19 and COVID-19-like Black Swan incidents

“…Escobar et al performed an epidemiological study, after eliminating the potential confounding factors such as the COVID-19 epidemic stages, geographical distribution, population density, and age structure, they found a 10% increase in the BCG index resulted in a 10.4% decrease in COVID-19 deaths [88] . Interestingly, a large number of subsequent ecological studies have found a similar phenomenon that BCG vaccination rates and years of implementation of the BCG vaccination policy are significantly negatively correlated with COVID-19 morbidity and mortality [14] , [89] , [90] , [91] , [92] , [93] , [94] , [95] , [96] , [97] , [98] , [99] , [100] , [101] , [102] , [103] , [104] , [105] , [106] , [107] , [108] , [109] , [110] , [111] , [112] , [113] .…”

Comprehensive Survey of IoT, Machine Learning, and Blockchain for Health Care Applications: A Topical Assessment for Pandemic Preparedness, Challenges, and Solutions

“…In addition, the developed solution utilizes recent data for enhancing CT images diagnosis and detection accuracy. Remarkable applications of emerging technologies used to defeat COVID-19 are discussed in the upcoming subsection [169][170][171].…”

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“…9 The same may apply to studies that are using disparate data sets from a later stage of the COVID-19 pandemic and conclude the vaccinated countries to be more protected while overlooking the presence of countries with minimal COVID-19 effect in no BCG vaccination policy countries as well. 10 Similarly, the studies trying to correlate childhood BCG vaccination to higher COVID-19 incidence or as a risk factor are also potentially indefensible due to gross overlooking of the basic facts about the longevity of trained…”