In February 1942 jaundice appeared among U.S. soldiers in Hawaii, Alaska, Iceland, England and half the training camps at once. The common factor was the Army's yellow fever vaccine, stabilized with human serum carrying hepatitis B. About fifty thousand soldiers were hospitalized, and the board built to study the outbreak lasted past the war, partly through deliberate infection of conscientious objectors.
The exact number of 1942 cases caused by the vaccine is unknowable, and official records give 84 deaths as a probable minimum. Whether an Army hepatitis center was ever built in Germany is unconfirmed.