Formation of secretory and circulating antibodies after immunization with live and inactivated influenza virus vaccines.

The formation of secretory and circulating antibodies in volunteer teenagers and adults immunized intranasally with live and inactivated influenza virus vaccines has been studied. The antibody response to the vaccine was directly dependent upon the amount of virus contained in the inoculum. The live vaccine was more effective than the inactivated vaccine in stimulating the production of secretory antibodies. Antibody levels in serum before immunization did not affect the production of secretory and circulatory antibodies. However, production of both of these antibodies was observed to be inversely correlated with the initial level of secretory antibodies. Secretory antibodies were shown to have a wider spectrum of activity against type A influenza viruses than circulating antibodies. Antibody titers in nasal secretions were correlated with the concentration of IgA in total protein but could not be correlated with concentrations of IgG.