Susceptibility of a yak to influenza A viruses and presence of H3N2 antibodies in animals in Nepal and India.

Naturally acquired antibody to H3N2 human influenza antigens was found in a yak-zebu crossbred in Nepal. Serial inoculation of a yak, negative for antibody, produced a response to A/Hong Kong/1/68 (H3N2), A/England/42/72 (H3N2), and A/Prague/1/56 (Heq1 Neq1) influenzavirus strains. Single radial diffusion tests showed that cattle and goats in West Bengal, India, and water buffaloes and cattle in Kathmandu, Nepal, also had antibodies against the H3N2 antigens. Haemagglutination-inhibition antibodies to equine influenzaviruses were not found in human, goat, cattle, chicken, and dog sera, nor were antibodies to avian viruses found in human or equine serum.