Clinical trial of safety and immunogenicity of new influenza vaccine Grifor in children]

Assessment of reactogenicity, safety and immunogenicity after single intramuscular immunization of children with Grifor vaccine.Reactogenicity, safety, and immunogenicity of Grifor vaccine compared with Vaxigrip vaccine was evaluated during phase III clinical trial in the Institute of Influenza. Thirty-six children aged 12 - 17 years, divided on 2 groups, participated in single blind comparative prospective randomized trial. Seroconversion factor, seroconversion and seroprotection levels were evaluated by hemagglutination inhibition assay.Results of study of systemic and local reactogenicity in children during first 7 days after immunization with Grifor and Vaxigrip vaccine showed good tolerability, areactogenicity and safety of both vaccines. Complete blood count, serum biochemistry and urinalysis results as well as serum IgE level did not change after vaccination. After immunization with Grifor vaccine, seroconversion rate to influenza virus subtypes A/H1N1, A/H3N2, and B was 70%, 50%, and 70% respectively, seroprotection rate--90%, 80%, and 85% respectively, and seroconversion factor--6.5, 2.7, and 4.0 respectively.This trial, which was performed in tightly controlled conditions, had demonstrated that Grifor vaccine is safe and highly immunogenic against influenza viruses A and B and satisfies criteria of both Federal Service for Surveillance for Protection of Consumers Rights and Human Welfare and CHMP of EMA. Obtained results allow to recommend the Grifor vaccine for use in pediatric practice according to national immunization schedule.