Mandated TB vaccination predicts flattened curves for COVID-19 spread

Summary: Researchers report that if the US had adopted mandatory BCG vaccines against tuberculosis decades ago, we may not have reached death rates in triple digits for coronavirus. Countries that have a current policy mandating BCG vaccinations have significantly slower growth of both COVID-19 cases and deaths compared to countries with no mandates for the TB vaccination.

Source: University of Michigan

If the United States had mandatory tuberculosis vaccination in place several decades prior, the total number of coronavirus-related deaths might not have reached triple digits by late March.

In fact, according to a new University of Michigan report, the U.S. would have suffered an estimated 94 deaths, which would have been only 4% of the actual death toll of 2,467 in this country on March 29.

The report—titled “Mandated Bacillus Calmette-Guérin (BCG) vaccination predicts flattened curves for the spread of COVID-19″—is an analysis of daily reports of COVID-19 cases and related deaths in more than 50 countries.

Researchers say countries that have a current policy mandating BCG vaccination, a TB vaccine, have significantly slower growth of both cases and deaths, as compared to all other countries.

The preprint article, which is currently under review, builds on prior evidence that the BCG vaccination—typically given at birth or during childhood—offers a long-lasting protective effect not only against tuberculosis but also against various other infectious diseases.

BCG may be effective when a substantial proportion of the population is made resistant to a virus. That is to say, the spread of the virus may be slowed only when there is “herd immunity” that prevents the virus from spreading easily across the population, said Martha Berg, the study’s lead author and a U-M psychology graduate student.

Berg and colleagues analyzed daily reports of confirmed cases and deaths during a 30-day period, modeling differences between growth curves in countries that have mandated BCG policies at least until very recently (such as Brazil, Ireland, France and India) and countries that do not (such as the U.S., Italy and Lebanon).

This shows a graph from the study
The study further observed that vaccination may be seen as a prosocial act.The image is credited to the researchers.

While the new report contributes to research involving TB vaccinations, it also noted some limitations; for example, some countries may have better quality data regarding the number of coronavirus cases and deaths than others. In addition, since BCG is given early in life, it’s unclear whether the vaccination might be effective when given to adults nor how long it might provide immunity to COVID-19.

“Moreover, it is uncertain whether BCG might have any adverse effects when given to those already infected with COVID-19,” Berg said. “There is an urgent need for randomized clinical trials.”

The study further observed that vaccination may be seen as a prosocial act. People who are not vaccinated can be protected as long as enough other people are, especially in the U.S., which does not mandate BCG.

“Cultural norms emphasizing prosocial interdependent orientations may prove to be crucial for the success of BCG in preventing future outbreaks of COVID-19,” Berg said.

The study’s co-authors are U-M psychology graduate students Qinggang Yu, Cristina Salvador and Irene Melani, and psychology professor Shinobu Kitayama.

About this coronavirus research article

University of Michigan
Media Contacts:
Calli McMurray – University of Michigan
Image Source:
The image is credited to the researchers.

Original Research: The full open access paper, “Mandated Bacillus Calmette-Guérin (BCG) vaccination predicts flattened curves for the spread of COVID-19” is available to download (PDF).

Feel Free To Share This COVID-19 News.

Join our Newsletter
I agree to have my personal information transferred to AWeber for Neuroscience Newsletter ( more information )
Sign up to receive our recent neuroscience headlines and summaries sent to your email once a day, totally free.
We hate spam and only use your email to contact you about newsletters. You can cancel your subscription any time.