Abstract
Virus vaccines with AlPO4, HA [hemagglutination] vaccines and HA vaccines with AlPO4 were prepared as monovalent suspensions using 4 strains of influenza A and 2 of influenza B and tested in mice, rabbits and humans. In all cases, dilutions of the HA vaccines induced lower antibody levels and lower levels of immunity than their virus counterparts. Addition of AlPO4 restored the antigenicity of HA vaccines to levels almost equal to those of whole virus vaccines. The significance of these findings is briefly discussed.