Hepatitis Virus: Effect of Heat on the Infectivity and Antigenicity of the MS-1 and MS-2 Strains

A serum pool containing the MS-1 strain of viral hepatitis, type A (IH) was boiled for 1 min at a temperature of 98 C. The heated serum was neither infectious nor immunogenic; it did not protect susceptible individuals who were infected by the unheated MS-1 serum pool S months later. A serum pool containing the MS-2 strain of viral hepatitis, type B (SH) was boiled for 1 min at 98 C. This treatment modified infectivity with out affecting antigenicity. The complement-fixation titer of hepatitis-associated antigen was not significantly affected by the heating.