PURIFIED INFLUENZA-A VIRUS N2 NEURAMINIDASE VACCINE IS IMMUNOGENIC AND NONTOXIC IN HUMANS

The immunogenicity and toxicity of a purified influenza vine (N2) neur aminidase vaccine (NAV) were investigated in 88 human subjects aged 18 -40, and compared to response to a conventional trivalent influenza va ccine, Fluogen (Parke-Davis). NAV doses ranged from 2.6 to 69.9 mu g a nd were given intramuscularly. Serologic neuraminidase-inhibiting (NI) and neuraminidase-specific ELISA responses in this N2-primed populati on were roughly proportional to the dose administered Maximal response was seen in 14-21 days and NI antibody titers persisted unabated for the 6-month post-vaccination follow-lip period. All doses were well to lerated with respect to local and systemic reactions. NI tests perform ed with the putative (1975) priming N2 antigen demonstrated anamnestic response but did not reveal responses not already shown with the homo logous (1992) antigen. Response to this purified, non-adjuvanted prepa ration encourages continuing investigation of the induction of infecti on-permissive immunity with influenza virus neuraminidase.