An anecdote told by Dr. Ernest Bueding, who was working at the Pasteur Institute in Paris in 1934: A new yellow fever vaccine had been discovered there but not fully tested for side-effects, when "a doctor from Colmar" telephoned for information about the new drug.

On hearing of the possibility of side-effects he came to Paris the next day and insisted on being injected with the vaccine himself, despite strong warnings that this was unwise at the age of fifty-nine. Schweitzer, who of course had been recognized by this time, was very impatient when the Institute hospitalized him for two days as a precaution. But he suffered no serious reactions and immediately put in an order for the vaccine.