A study of the main parameters of immunogenicity of Ultrix vaccine

Aim. Clinical trial of Ultrix vaccine of OOO FORT manufacture containing different serotypes of influenza virus: H1N1 A/California/7/2009 (H1N1) pdm 09, H3N2 A/HongKong/ 4801/2014, NYMCX-263B(15/184) and B/Brisbane/60/2008 NYMCBX-35 (15/300) Victo-rialineage strains (epidemiological season of 2016) and H1N1 A/Michigan/45/2015 NYMCX-275 (16/248), H3N2 A/HongKong/4801/2014, NYMCX-263B(15/184) иB/Brisbane/60/2008 NYMCBX-35 (15/300) Victorialineage strains (epidemiological season of 2017). Materials and Methods. A study of the basic parameters of immunogenicity included determination of the geometric mean value of the antibody titer, of seroprotection and seroconversion and of relative number of individuals with 4-fold increase in the antibody titer after vaccination. Immunogenicity was determined by a micromethod in hemagglutination inhibition reaction. Sera were tested with diagnosticums obtained from serotypes of influenza virus identical to vaccinal strains. Results. The level of seroprotection with Ultrix made 91.7-95.8% (2016) and 93.8-97.9% (2017). The maximal level of seroprotection was achieved in 6 months after vaccination with Ultrix containing H1N1A/California serotype. 2.55-4.36-Fold increase in the geometric mean value of anti-HA to all vaccinal strains was found in vaccination in 2016 and 2017, and 4-fold increase in antibody titer in more than 70% of volunteers on the 21st day after the first immunization in 2016. Conclusion. The obtained results of clinical trials of Ultrix vaccine with different antigenic composition confirms the correspondence of the immunogenicity parameters of the drug to the requirements of the Committee for Proprietary Medical Products (CPMPEMEA, CPMP/ EWP/1045/01) and of State Pharmacopoeia of RF of XIII edition (SP SP XIII).