COMPARISON OF US INACTIVATED SPLIT-VIRUS AND RUSSIAN LIVE ATTENUATED,COLD-ADAPTED TRIVALENT INFLUENZA VACCINES IN RUSSIAN SCHOOLCHILDREN

In a blinded, placebo-controlled study, the reactogenicity, immunogeni city, and clinical efficacy of single doses of US inactivated split-vi rus and Russian live attenuated, cold-adapted influenza vaccines were compared in 555 schoolchildren in Vologda, Russia. Serial serum sample s were collected and school absenteeism was assessed. Systemic reactio ns were rare, but local reactions (primarily erythema at the injection site) were observed in 27% of the inactivated vaccine group, and cory za (12%) and sore throat (8%) were observed in the attenuated vaccine group, At 4 weeks after vaccination, a greater than or equal to 4-fold rise in titer of hemagglutination inhibition antibody to A (H1N1), A (H3N2), and B was noted, respectively, among 78%, 88%, and 53% of chil dren who received inactivated vaccine and among 55%, 79%, and 30% of c hildren who received attenuated vaccine. The vaccine efficacy for prev enting school absenteeism due to acute respiratory illness during the period of peak influenza activity was 56% for inactivated vaccine and 47% for attenuated vaccine.