Voprosy virusologii
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Voprosy virusologii · May 1994
Comparative Study Clinical Trial Controlled Clinical Trial[A comparative study of live and inactivated influenza vaccines: the organization of the observation and the results of a study of their reactogenicity and immunogenicity].
Schoolchildren of 30 to 34 schools of Novgorod were vaccinated over a three-year period with Russian live cold-adapted attenuated vaccine for children and whole-virus inactivated vaccines and placebo for comparative field study of the vaccines properties and efficacy. In control trials both bi- and trivalent live attenuated vaccines were well tolerated and areactogenic. A whole-virus inactivated trivalent vaccine induced mild and moderate fever and local reactions in 2-4% of the vaccinees. ⋯ The pattern of the results was similar to that in revaccinated children with preexisting antibody at a level of 1:20, but much lower in children with the initial titre above 1:20. After the 3rd year of vaccination the immune response of the vaccinees was similar, most of the results depending on the initial antibody titre and also on the change of vaccine strains. This raises a question of the expediency of annual influenza revaccination of the same person after 2 years of successful immunization and of the necessity of vaccine strains replacement after 2-3 years of use.