A New Study Offers One Explanation for Why India Has Fewer Covid19 Cases Than U.S., Italy
In India, millions of children are administered the Bacillus Calmette-Guérin (BCG) vaccine to protect against tuberculosis soon after birth. Now, scientists have suggested the BCG vaccine may provide broad viral immunity that offers some protection against Covid19, a finding further solidified in a new study spanning 178 countries.
Medical researchers from the U.S. and the U.K. assessed Covid19 cases and related fatalities for 15 days from March 9 to March 24, across countries with a universal BCG vaccination policy such as India (that has the world’s largest TB burden) and in countries that do not administer the BCG vaccines to newborns, such as the United States and Italy. Scientists found the incidence of Covid19 cases was a mere 38.4 per million people in countries with a BCG vaccination policy, and a whopping 358.4 per million people in countries without. Moreover, the death rate in the former was found to be 4.28 per million, compared to 40 per million in the latter.
As medical researchers the world over scramble to find a Covid19 vaccine, the new research backing up previously-made assumptions about the efficacy of the BCG vaccine in fighting the coronavirus pandemic is a welcome respite. Four countries — Australia, Germany, the Netherlands, and the United Kingdom — have already begun human trials to test the vaccine on the novel coronavirus. The German researchers, for example, had already established the efficacy of a licensed BCG vaccine in protecting mice against viral infections in the respiratory tract, The Swaddle reported earlier.
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For now, the vaccine will mostly be administered to healthcare workers administering care to Covid19 patients on the frontlines, in the hopes they’ll develop BCG-induced immunity to the virus, according to scientists.
In the long run, only extensive, controlled human trials will be able to tell just how effective the BCG vaccine is in strengthening people’s immunity against the novel coronavirus. While the numbers show a correlation between the presence of a BCG vaccine and fewer Covid19 cases and deaths, we cannot immediately assume causation, especially because the strict and accurate reporting of Covid19 numbers varies from country to country. Nonetheless, the new findings have been described as a small, but promising, ray of hope in this fight.
“It is ironic that one of our oldest immunotherapies (BCG, used in India for decades) might help against the newest threat facing our civilization,” professor of Urologic Oncology and cancer research at MD Anderson Cancer Center in Houston, Texas, and one of the study authors, Ashish Kamat, told The Economic Times.