COMPARATIVE TRIAL OF LARGE-PARTICLE AEROSOL AND NOSE DROP ADMINISTRATION OF LIVE ATTENUATED INFLUENZA VACCINES

Healthy adult subjects (n = 198) were randomized to receive bivalent c old-adapted (ca) influenza A vaccine containing 10(7.4)TCID50 each of A/Kawasaki/9/86 (H1N1) and A/Los Angeles/2/87 (H3N2) by either nose dr ops (ND) or large-particle aerosol (LPA). All subjects had received mo novalent inactivated influenza B vaccine intramuscularly in the previo us year. Ninety percent of LPA recipients and 82% of ND recipients pre ferred intranasal administration to their previous experience with int ramuscular vaccine. Twenty-six (27%) of 98 LPA recipients and 47 (49%) of 97 ND recipients reported swallowing vaccine (P = .008). Fever was observed uncommonly (less-than-or-equal-to 5%), and incidence of resp iratory symptoms was comparable between groups. Four-fold or greater h emagglutination antibody response to at least one of the influenza A v accine viruses was significantly more frequent after LPA (64%) than ND vaccination (43%; P = .005). LPA administration of ca influenza to th e nasopharynx was well tolerated, safe, and more immunogenic than ND d elivery.