MULTIDOSE, LIVE ATTENUATED, COLD-RECOMBINANT, TRIVALENT INFLUENZA VACCINE IN INFANTS AND YOUNG-CHILDREN

Twenty-two healthy infants and children received either cold-recombina nt, trivalent influenza vaccine or placebo in a three-dose vaccine tri al. Most (82%) who received vaccine were seronegative to all three vac cine strains (10(6) TCID50/dose each): A/Kawasaki/9/86 (H1N1), A/Los A ngeles/2/87 (H3N2), and B/Yamagata/16/88. Vaccine was administered int ranasally at time 0 and 2 and 4 months later. The vaccine was well tol erated and immunogenic when administered in a multidose regimen. The f irst dose stimulated antibody to H1, H3, and B in 59%, 94%, and 35% of vaccinees, respectively, by hemagglutination inhibition (HAI) or ELIS A. After two doses of vaccine, 93%, 93%, and 80% had antibody by HAI o r ELISA to H1, H3, and B, respectively. Most vaccinees (67%) responded to all three viruses after two doses of vaccine. The third dose contr ibuted little to the vaccine's immunogenicity. Multidose trivalent inf luenza vaccine is safe and induces an immune response in most vaccinee s after two doses.