dc.description.abstract | The immunogenicity of experimental polyvalent subunit vaccine against the influenza viruses, types A/H1N1, A1 /H3N2/ and B was studied in a biological assay on 15 experimental female rabbits, of the chin-chilla breed, weighing 700g, and 33 experimental mice, (BALB/C females), weighing 20 g. The experimental subunit vaccine was prepared from purified glycoprotein subunits isolated from outer envelopes of the influenza viruses, types A/Singapore/6/86 H1N1, A1/Peking/353189 H3N2 and B/Hamagota/45/90. Antigens were adsorbed on the adjuvant A1(OH)3, dissolved in 100 mmol/l of PBS. The finalconcentration of the adjuvant in the vaccine was 5 mg/ml. The haemagglutinating activity of isolated glycoprotein subunits in the vaccine was 128 HJ/0.1 ml. The samples of purified glycoprotein antigens, isolated from the above mentioned influenza viruses, with total protein concentrations of 0.20, 0.154 and 0.20 mg/ml, had significant haemagglutinating activities of 256 - 512 HJ/0.1 ml. The samples of nondisrupted and purified influenza virions (before the isolation of glycoprotein subunits), with higher total protein concentrations of 0.44. 0.30 and 0.53 mg/ml had haemagglutinating titres from 128 - 256 HJ/0.1 ml. One group of 10 experimental rabbits was immunized with 0.5 ml subunit vaccine (s/c per animal) and revaccinated with the same dose 24 days after the first vaccination. The mean geometric titres of HI antibodies (GMT) log 2/25 μl) against influenza viruses A/H1N1/, A1/H3N2/ and B in the sera of these experimental rabbits on day 7 after vaccination were 2.5; 2.0 and 2.5; on day 14: 3.5;3.0 and 3.0; on day 21: 4.0; 3.5 and 3.0; on day 28: 4.5; 4.0 and 3.5. In the blood sera of 5 control nonvaccinated rabbits, virusneutralizing HI antibodies were not detected. A group of 12 mice was immunized with 0.5 ml of the polyvalent influenza subunit vaccine (s/c per animal). The mean geometric titres of HI antibodies (GMT log 2/25 μl) against influenza viruses type A/H1/N1/, A1/H3/N2/ and B in the sera of immunized mice, on day 21 after vaccination were 4.6; 4.3 and 3.5. In the sera of 7 nonimmunized mice, virusneutralizing HI antibodies were no detected. Seven experimental mice were artificially infected 21 days after vaccination with a suspension (1 ml) of the above mentioned types of influenza viruses adapted to mice, with the titre EID 50 = 10-8.5 (for each type) intraperitoneally (i/p) and paranasally (p/n). An 7 vaccinated and artificially infected mice survived this infection without any symptoms. A second group of7 nonvaccinated control mice was artificially infected in the same way. All the animal were taken ill with acute respiratory infection 7 days later and 3 animale died on day 10 of the experiment. | en |