Countries with high deaths due to flu and tuberculosis demonstrate lower COVID-19 mortality: roles of vaccinations

ABSTRACT

Deaths due to the ongoing COVID-19 pandemic vary (3–1681 deaths/million and mortality rates 0.71–14.54%) and are far greater in some countries compared to others. This observation led us to perform epidemiological analysis, using data in the public domain, to study the correlation of COVID-19 with the prevalence and vaccination strategies for two respiratory pathogens: flu and tuberculosis (TB). Countries showing more than 1000 COVID-19 deaths were selected at three time points during the ongoing pandemic: 17 May, 1 October and 31 December 2020. The major findings of this study that are broadly consistent at all three time points are: First, countries with high flu deaths negatively correlate with COVID-19 deaths/million. Second, TB incidences and deaths negatively correlate with COVID-19 deaths/million. Countries displaying high TB and flu deaths (Nigeria, Ethiopia, Myanmar, Indonesia, India) display lower COVID-19 deaths/million compared to countries with low TB and flu deaths (Italy, Spain, USA, France). Third, countries with greater flu vaccination display lower flu incidences but higher COVID-19 deaths/million and mortality rates. On the other hand, Bacillus Calmette Guerin (BCG) vaccination negatively correlates with Covid-19 deaths/million. Fourth, countries with only BCG, but no flu, vaccination show delayed and lower number of COVID-19 deaths/million compared to countries with flu, but no BCG, vaccination. Fifth, countries with high BCG vaccination coverage as well as high TB deaths display the lowest COVID-19 deaths/million. The implications of this global study are discussed with respect to the roles of respiratory infections and vaccinations in lowering COVID-19 deaths.

KEYWORDS:

• BCG
• COVID-19
• flu
• tuberculosis
• vaccinations

Acknowledgments

We thank Dipankar Ghosh (JNU, Delhi), D.N. Rao (IISc, Bangalore) and Soumen Basak (NII, Delhi) for encouraging us to work on COVID-19. The interactions and comments on our study by Shamik Majumdar (NIH, USA), Arvind Sahu (NCCS, Pune), B. Ravindran (ILS/NISER, Bhubaneshwar), Ramray Bhat (IISc, Bangalore), Udaykumar Ranga (JNCASR, Bangalore), Amit Singh (IISc, Bangalore), Vrinda Nandi (Bangalore) and all members for the DpN laboratory are gratefully appreciated. This work was conceived during the pandemic months of April–May 2020 and we thank the DBT-IISc partnership program for funding our innate curiosity.

Disclosure of potential conflicts of interest

No potential conflicts of interest were disclosed.

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website at https://doi.org/10.1080/21645515.2021.1908058

Additional information

Funding

This work was supported by the Department of Biotechnology, Ministry of Science and Technology [BT/PR27952-INF/22/212/2018].