A serologic follow-up of the 1942 epidemic of post-vaccination hepatitis in the United States Army.

An epidemic of icteric hepatitis in 1942 affected approximately 50,000 U.S. Army personnel. This outbreak was linked to specific lots of yellow-fever vaccine stabilized with human serum. To identify the responsible virus and the consequences of the epidemic, during 1985 we interviewed and serologically screened 597 veterans who had been in the army in 1942. These subjects were selected from three groups. Group I consisted of patients who had received the implicated vaccine and had jaundice; Group II had received the implicated vaccine but remained well; Group III had received a new, serum-free vaccine, with no subsequent jaundice. Ninety-seven percent of Group I, 76 percent of Group II, and 13 percent of Group III were positive for antibodies to hepatitis B virus. Only one subject had hepatitis B surface antigen, for a carrier rate of 0.26 percent among recipients of the implicated vaccine. The prevalence of hepatitis A antibody was similar in all three groups, and no subject had antibody to hepatitis delta virus. We conclude that hepatitis B caused the outbreak, that about 330,000 persons may have been infected, that the hepatitis B virus carrier state was a rare consequence, and that the outbreak induced hepatitis B antibodies that appear to persist for life.