Clinical acceptability of live influenza vaccine in high risk subjects and children. Experience with three consecutive recombinant strains.

Reactogenicity and immunogenicity of three recombinant strains, Alice, RIT 4025 and RIT 4050, were re-examined by a retrospective analysis of the data from clinical trials and routine vaccination campaigns. Special emphasis was put on the acceptability of vaccinal strains for the elderly, patients with chronic pulmonary diseases, subjects with atopy and children, as well as on the safety of repeated administrations of the vaccine to the general population. The incidence and nature of postvaccinal symptoms in high risk populations were similar to those observed in healthy subjects. Tolerance of the vaccine by children (2-10 years old) was excellent for both Alice and RIT 4050 strains. At the present time, we have evidence that the vaccine was administered to approximately 2500 subjects without any significant adverse effects, during the course of two or three consecutive vaccination campaigns. This holds true also for 12 vaccinees who received the vaccine for more than three years. The maximal number of doses administered to one person was 14. The vaccinal strains studied have been shown safe and immunogenic both in the general population and in high risk subjects and children.