TB vaccination may help flatten curves for COVID-19 spread

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In a new study, researchers found that 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, 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 research was conducted by a team at the University of Michigan.

The team did 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 study 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.

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. 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.

The lead author of the study is Martha Berg, a U-M psychology graduate student.

The study is published here.

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