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Citizen science initiative points at childhood BCG vaccination as a risk factor for COVID-19

José de la Fuente1,2, Octavio Armas3, Luis Sánchez-Rodríguez3

  • 1SaBio, Instituto de Investigación en Recursos Cinegéticos IREC-CSIC-UCLM-JCCM, Ciudad Real, Spain.

Transboundary and Emerging Diseases
|April 7, 2021
PubMed

Insights

Bacille Calmette-Guérin (BCG) vaccination may increase the risk of contracting COVID-19, especially in individuals vaccinated during childhood. This finding suggests a potential link between BCG and heightened susceptibility to the virus.

Area of Science:

  • Immunology
  • Epidemiology
  • Public Health

Background:

  • Existing research lacks conclusive evidence on the impact of Bacille Calmette-Guérin (BCG) vaccination on COVID-19 outcomes.
  • The role of BCG vaccination in the context of the COVID-19 pandemic requires further investigation.

Purpose of the Study:

  • To analyze factors and characteristics of individuals affected by COVID-19 in relation to BCG vaccination status.
  • To investigate the potential association between BCG vaccination and COVID-19 risk using a global citizen science approach.

Main Methods:

  • A worldwide citizen science initiative collected data from 1,233 individuals between October 2-30, 2020.
  • Structured data collection focused on analyzing factors, characteristics, and BCG vaccination status of individuals diagnosed with COVID-19.

Main Results:

  • The study suggests that BCG vaccination may increase the risk of COVID-19, particularly in individuals vaccinated during childhood.
  • Childhood BCG vaccination was associated with a fivefold increased likelihood of COVID-19 diagnosis in low-incidence countries and threefold in high-incidence countries.
  • Innate immunity mechanisms and inflammatory reactions are proposed as potential explanations for this observed association.

Conclusions:

  • Childhood BCG vaccination might be a risk factor for developing COVID-19.
  • The findings highlight the need to consider BCG vaccination status in epidemiological analyses of the COVID-19 pandemic.
  • Further research is warranted to elucidate the immunological mechanisms underlying the potential link between BCG and COVID-19 risk.

Keywords:
BCG vaccineCOVID-19citizen sciencehumansinnate immunitypandemicsrisk factorssevere acute respiratory syndrome coronavirus 2vaccination

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