A serologic recapitulation of past experiences with influenza A; antibody response to monovalent vaccine.

The results of the present study provide a striking demonstration of antibody orientation produced by the dominant antigens of the strains of influenza virus encountered at childhood. The homologous and heterologous antibody response to monovalent vaccines containing swine, PR8, FM1, or Cuppett viruses show that the antibody-forming mechanisms of children born after 1943 are oriented to strains of influenza A-prime; of recruits to strains of influenza A; and of persons over 30 years of age to a strain of swine influenza. It was shown that antibody response to heterotypic viruses appears to provide a serologic index of the amount of experience each of the segments of the general population studied have had with antigenic variants of influenza virus. Finally it was demonstrated that the antibody response of humans to strains of influenza A or influenza A-prime is remarkably uniform for isolates of each antigenic type.