BCG is first and foremost the world’s most common tuberculosis vaccine, and was first used in humans all the way back in 1921. Made from a weakened strain of live bovine tuberculosis bacteria, it’s been show to be up to 80 percent effective in preventing TB for a duration of 15 years, depending on geographical location. That’s pretty impressive, which is why—US aside—it’s shoved into many a childhood arm around the world. But that’s just the beginning.
Jumping from TB to cancer is quite a leap, but it’s one BCG has made time and again. As far back as 1979, a clinical trial declared that “BCG is beneficial in the treatment of lung cancer”. Then, in 1991, a study published in the new England Journal of Medicine suggested that the BCG vaccine offered strong protection against the recurrence of bladder cancer.
There’s a lot more, and if the article’s to be believed, we’ve barely scratched the surface of what the drug can do.