Significantly improved COVID-19 outcomes in countries with higher bcg vaccination coverage: A multivariable analysis

Danielle Klinger, Ido Blass, Nadav Rappoport*, Michal Linial*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

50 Scopus citations


The COVID-19 pandemic that started in China has spread within 3 months to the entire globe. We tested the hypothesis that the vaccination against tuberculosis by Bacille Calmette–Guérin vaccine (BCG) correlates with a better outcome for COVID-19 patients. Our analysis covers 55 countries complying with predetermined thresholds on the population size and number of deaths per million (DPM). We found a strong negative correlation between the years of BCG administration and the DPM along with the progress of the pandemic, corroborated by permutation tests. The results from multivariable regression tests with 23 economic, demographic, health-related, and pandemic restriction-related quantitative properties, substantiate the dominant contribution of BCG years to the COVID-19 outcomes. The analysis of countries according to an age-group partition reveals that the strongest correlation is attributed to the coverage in BCG vaccination of the young population (0–24 years). Furthermore, a strong correlation and statistical significance are associated with the degree of BCG coverage for the most recent 15 years, but no association was observed in these years for other broadly used vaccination protocols for measles and rubella. We propose that BCG immunization coverage, especially among the most recently vaccinated population, contribute to attenuation of the spread and severity of the COVID-19 pandemic.

Original languageAmerican English
Article number378
Pages (from-to)1-14
Number of pages14
Issue number3
StatePublished - Sep 2020

Bibliographical note

Funding Information:
This research received no external funding. The Center for Interdisciplinary Data Science (CIDR), at the Hebrew University partially contributed D.K and I.B fellowship. Acknowledgments: We thank the biomedical community for valuable comments for the original version in MedRxiv. We thank Herve Bercovier for his comments and for sharing with us the fascinating history of the BCG. We thank Nati Linial and the Linial’s lab for suggestions and fruitful discussions.

Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.


  • Coronavirus
  • Demography
  • Epidemiology
  • MMR vaccine
  • Multivariable regression
  • SARS-CoV-2
  • Tuberculosis


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