Clinical Trials with Inactivated Monovalent (A/New Jersey/76) and Bivalent (A/New Jersey /76-A/Victoria/75) Influenza Vaccines in Los Angeles Children

Clinical and serologic responses to inactivated influenza virus vaccines were studied in 444 children in Los Angeles under double-blind, placebo-controlled protocols. Oneand two-dlose regimens employing monovalent (A/New Jersey/76) and bivalent (A/New Jersey/76-A/ Victoria/75) vaccine were studied in separate trials. In a single dose, whole-virus vaccines were more potent than split-product vaccines as primary inducers of immunity against influenza ANew Jersey/76 virus. Split-product vaccines were better tolerated clinically and, after two-dose regimens, produced rates of seroconversion (>90%) against A/New Jersey/76 virus comparable to those produced by two doses of whole-virus vaccines. Analysis of heterotypic antibody responses induced by monovalent A/New Jersey/76 vaccines revealed only slight increases in antibody against influenza A/Victoria/75 virus. After vaccination with bivalent vaccines, levels of antibody against influenza A!Victoria/ 75 virus were significantly higher in subjects who received high doses of split-product vaccines than in subjects who received whole-virus vaccines.