A century-old tuberculosis vaccine that also offers protection against a variety of other infections could play a role in preventing coronavirus deaths or severe illness from the disease that has ravaged the nation and the world.
The Bacillus Calmette-Guerin vaccine has been widely used in developing countries to protect against tuberculosis since its introduction in 1921.
It’s the most widely administered vaccine in the history of medicine and just last year was given to 120 million newborns worldwide, according to the World Health Organization.
But about 10 years ago, scientists started to notice “off-target effects” of the vaccine, “It was offering a survival advantage against unrelated infections,” said Dr. Denise Faustman, director of immunobiology at Massachusetts General Hospital.
BCG was found to protect against respiratory, viral, parasitic and bacterial infections, said Faustman, who has been working on multiple clinical trials using the drug to treat type 1 diabetes.
The vaccine was never given to Americans and isn’t currently available in the country as it is not produced here and tests for tuberculosis can be conducted in other ways.
Many residents of other countries that have been hit hard by coronavirus also never got the vaccine. “In the countries where BCG was never given or stopped 50, 60 years ago — the mortality is off the charts,” said Faustman, citing Spain and Italy.
But looking at countries in which residents get the vaccine such as Japan, Taiwan and India, “there’s very little effect so far with COVID,” said Faustman, adding that a clinical trial must be done to prove those impacts are from BCG.
BCG vaccination studies show the drug works by changing the primary, innate immune system, which can elicit a stronger response to infections.
Some human clinical trials have shown BCG reduced the incidence of acute upper respiratory tract infections in adults by 70% to 80% and another showed that in high-mortality settings, BCG vaccination reduced all-cause infant mortality by more than a third.
Now it’s time to get BCG clinical trials started here in the U.S. and Faustman said she is hoping to start within the next month.
The trial would include high-risk health care workers as participants and results could be seen in less than a year, according to Faustman.
“We have a strain of BCG that is known to be extraordinarily potent so now we are in the process of getting things started,” Faustman said.