Following the instillation of live influenza type A2 (Hong Kong) virus into the respiratory tract, dolphins developed high antibody titers measured by the hemagglutination-inhibition and complement fixation tests. The sera of dolphins are usually anticomplementary but this activity could be removed by precipitation at low iconicity. The earliest antibody was a macroglobulin and with time there was a shift to formation of antibodies of the 7 S class.

Sera from several dolphins and from a killer whale reacted in the complement fixation test with the antigens of adenovirus, type 4, Coxsackie virus, type A7, poliovirus, type I, and mumps virus.