Authors: Lucy Chard (Future Science Group)
A newly published study from Ben-Gurion University of the Negev (Beersheba, Israel) and the Hebrew University of Jerusalem (Israel) shows that countries where a tuberculosis vaccine has been administered in the past 15 years have demonstrated significantly improved outcomes in regard to the COVID-19 pandemic.
The study analyzing the correlation between the Bacille Calmette-Guérin (BCG) vaccine for tuberculosis and COVID-19 outcomes has been published in Vaccines. The results show that where BCG regimes were in place, infection rates and death rates per million associated with COVID-19 were significantly reduced. This was particularly obvious in patients aged 24 years or younger, who had received the BCG vaccine within the last 15 years. There was no such correlation in older adults however.
“Our findings suggest exploring BCG vaccine protocols in the context of the current pandemic could be worthwhile,” stated Nadav Rappoport of Ben-Gurion University of the Negev and a lead researcher on the study. “A growing number of clinical trials for testing the efficacy of BCG vaccination have been initiated.”
The study included data from 55 countries, all with populations of over 3 million, representing roughly 63% of the world’s population. The team used a webtool to configure the starting dates of the countries (as the pandemic hit at different dates across the world) by taking the first date where the country’s death rate reached 0.5 deaths per million and upwards. Other confounding factors, including demographic, economic, pandemic-restriction-related, and country health-based factors, were controlled for. Across all 55 countries, administration of the BCG vaccine was consistently shown to be associated with improved outcomes in COVID-19 patients.
This finding prompted the team to look into the effects of vaccination of populations with measles and rubella vaccines, to see if these also gave rise to an increase in positive outcomes of COVID-19. The results in these cases did not show any significant effects of the previous vaccines on COVID-19 outcomes.
In past epidemiological studies into the BCG vaccine, it has been shown to have effects further than just the treatment of tuberculosis, but little is known as to the reason why this vaccine is associated with such outcomes.
Sources: Klinger D, Blass I, Rappoport N, and Linial, M. Significantly improved COVID-19 outcomes in countries with higher BCG vaccination coverage: a multivariable analysis. Vaccines, 8, 378 (2020); www.eurekalert.org/pub_releases/2020-08/aabu-sic081220.php