Field trial with human and equine influenza vaccines in children: protection and antibody titres.

A placebo-controlled influenza vaccination trial was carried out on 374 children in the winter of 1967-68. The children were randomly vaccinated with 300 CCA of A2/England/1/1966, 300 CCA of A/equine 2/Miami/1963, or with a placebo. During this winter an influenza outbreak occurred, caused by A2/Nederland/1968. The A2 vaccine yielded a protection rate of 58% (P = 0.02) and the A/equine 2 vaccine a rate of 19% (P = 0.33). Serological data revealed that all influenza infections occurred in subjects who had a pre-epidemic haemagglutination inhibition titre below 150. The antibody response against various human influenza A2 viruses and against the horse strain (A/equine 2) is discussed.

RCT Entities:   Population Interventions Outcomes