[Effective methods of obtaining antisera to hemagglutinin H3].

Schedules for production of antisera to pure influenza A virus hemagglutinin (H3) in rats and rabbits are described. The antisera prepared in rats were shown to be better than rabbit sera as they had low levels of inhibitors readily eliminated by heating. The best sera were obtained by immunizations of rats into the tail. Both rat and rabbit antisera, in addition to the HI test, can be used satisfactorily in the immunodiffusion test and in radioimmunoassay.