Rabies is among the most terrifying viruses to get. According to the Centers for Disease Control, “once clinical signs of rabies appear, the disease is nearly always fatal.” (Really: there have been fewer than 10 documented cases of survival once symptoms appear.) Luckily for us—and our pets—Louis Pasteur developed a vaccine that can stop things from getting to that point.
The first time the vaccine was ever administered to a human being–on this day in 1885–was by Pasteur himself. Knowing that the disease was otherwise fatal, both doctor and patient (or, rather, patient’s mother) were willing to risk whatever harm might come from the injection, which had only been tested on dogs.
As TIME recounted in 1939:
By that fall, when his nation’s Academy of Sciences acknowledged the success, “hundreds of persons who had been bitten by mad dogs rushed to his laboratory.”
As for Meister? He ended up working as a janitor at the Pasteur Institute. There, TIME reported, Meister regaled visitors with tales of his time as the pioneering doctor’s patient: “I shall see always Pasteur’s good face focused on me,” he told them. He committed suicide in 1940, shortly after Germany invaded France—though, contrary to a prevalent myth, there is no evidence that he did so because he would rather die than allow the Nazis into the Institute.