Is BCG associated with reduced incidence of COVID-19? A meta-regression of global data from 160 countries

Abstract

Background Global research is running towards to find a vaccine to stop the threat of the COVID-19. The Bacillus Calmette–Guérin (BCG) vaccine that prevents severe forms of tuberculosis is getting more attention in this scenario. The objective of our study was to determine the association between BCG vaccine coverage and incidence of COVID-19 at a national-level across the Globe. Methods The data of 160 countries were included in the study. Meta-regression was done to estimate the difference in the incidence of COVID-19 cases between countries with BCG vaccination coverage. BCG coverage was categorized as ≤70%, >70% and no vaccination. The analyses were carried out by adjusting for factors such as population density, income group, latitude, and percentage of the total population under age groups 15–64 and above 65 years of each country. Results The countries that had ≤70% coverage of BCG vaccine reported 6.5 (95% CI: −8.4 to −4.5) less COVID-19 infections per 10,000 population as compared to countries that reported no coverage. Those that had >70% coverage reported 10.1 (95% CI: −11.4 to −8.7) less infections per 10,000 population compared to those with no BCG countries. Conclusion Our analysis suggests that BCG is associated with reduced COVID-19 infections if the BCG vaccine coverage is over 70%. The region-wise analyses also suggested similar findings, except the Middle East and North African region.

COVID-19 Severity and Neonatal BCG Vaccination among Young Population in Taiwan

“…Accordingly, there is a hypothesis that the substantial differences may be related to the universal BCG vaccination policies of these countries. Several ecological studies analyzed worldwide data before June 2020 and found that even after controlling for important country level factors such as temperature, total population size, population density, proportion of those aged 60 years or above, gross domestic product per capita, healthcare access and quality measures, COVID-19 testing numbers, and stringency level of the nationwide epidemic control policy, the BCG vaccination coverage rate and the total BCG vaccination implementation years among these countries are still significantly inversely correlated with the incidence and mortality of COVID-19 [5][6][7][8][9][10][11][12][13].…”

“…Whether BCG vaccination could have a beneficial effect against COVID-19 also under intense debate. Several ecological studies did suggest the potential protective effect of the universal BCG vaccination program on reducing COVID-19 morbidity and mortality [5][6][7][8][9][10][11][12][13]; some also implied that different BCG strains might vary in their protective ability [14]. In contrast, the inverse relation between COVID-19 disease burden and BCG vaccination was not observed by others [15,16].…”

Genetic Variants in Immune Related Genes as Predictors of Responsiveness to BCG Immunotherapy in Metastatic Melanoma Patients

“…With the ongoing COVID-19 pandemic, there have been reports that patients who are BCG-vaccinated are less susceptible to serious illness and have less severe COVID-19 symptoms [ 82 ]. Several studies are currently being conducted worldwide to determine whether BCG vaccination has a protective effect against COVID-19 ( #–NCT04537663, NCT04379336, NCT04369794, NCT04461379, NCT04347876) [ 82 , 83 , 84 , 85 ]. These studies indicate that the immunologic SNP panel could also be utilized as an important tool if BCG is preventative or can reduce the pathogenicity of COVID-19 as well as other infectious diseases.…”

Risikoabschätzung bei Patienten mit chronischen Atemwegs- und Lungenerkrankungen im Rahmen der SARS-CoV-2-Pandemie

“…who.int/teams/global-tuberculosis-programme/covid-19) dringend empfohlen. Epidemiologische Daten führten zu der Hypothese, dass durch die Tuberkuloseimpfung (BCG) ein Schutz gegen SARS-CoV-2-Infektionen und deren schwere Verläufe entstehen könnte [118,120]. Eine heterologe Schutzwirkung gegen andere Virusinfektionen wurde zwar beschrieben [121], ob diese auch für SARS-CoV-2 angenommen werden kann, ist bislang nicht bewiesen und wird aktuell in Studien geprüft.…”