This article describes the results of a pre-clinical study of immunogenicity and effectiveness of an inactivated pandemic vaccine (Refluvac®) on model mice. Mice received two 0.5 ml intraperitoneal inoculations with an interval of 14 days in three doses: containing 10.0, 5.0 and 2.5 μg HA (hemagglutinin) per animal. As a comparator preparation, the study used a semi-finished product (SP) vaccine diluted with phosphate buffered saline (PBS) to obtain HA concentrations of 5 μg and 10 μg. For a control group, the study used PBS as the negative control. We determined the vaccine’s protective effectiveness level by analysing its response in animals challenged with a pandemic А/California/7/09 (Н1N1) pdm09 virus. We assessed the immunogenicity of the vaccine by examining the mean geometric titre (GMT) of antibodies against the influenza virus as measured by hemagglutination-inhibition test (HAI). In the course of testing the GMT, we noted a dependence of the concentration of antibodies in serum on the vaccine’s antigen load. The highest GMT was observed in the group of mice vaccinated with a HA load of 10.0 μg – it amounted to 278.6 (95% CI, 135.6 to 572.4). We established a high tolerability of the vaccine tested. Our study shows that Refluvac® yields a high degree of protectivity against influenza A/H1N1 and prevents clinical signs, death or accumulation of influenza virus in the organs of vaccinated animals. There were deaths and clinical signs including general depression, hypodynamia and anorexia in the negative control group. The results of our study were used for the clinical study of the first Kazakhstan produced Refluvac® vaccine against pandemic A/H1N1 influenza virus.

Two recombinant influenza A virus vectors expressing the ESAT 6 and TB10.4 mycobacterial proteins from the non-structural (NS) gene were constructed via reverse genetics technique to develop a specific means of prophylaxis for bovine tuberculosis. We experimented to determine optimal conditions for growing recombinant vectors in Vero cell culture and chick embryos. This study established that the maximum amount of virus builds up in a Vero cell culture with the Dulbecco’s Modified Eagle’s Medium (DMEM) serum-free medium. However, using cell culture to produce vector vaccines is labour-intensive and inefficient. An alternative way, a traditional, time-tested technique, is provided by growing samples in chick embryos. One of the advantages of this technique is its affordability and availability, enabling easy scale-up of vaccine production. In the optimization experiments, the FLU-ΔNS_ESAT 6 and FLU-ΔNS_ТВ10.4 viruses constructed were inoculated into 10-day-old chick embryos. It was determined that the optimal incubation temperature that led to the highest virus build-up was 37 ± 0.5 °С. And the infectious activity level of the FLU-ΔNS_ESAT 6 recombinant vector was at 8.95 ± 0.07 log10EID50 0.2 cmE−3, while that of the FLU-ΔNS_ТВ10.4 was at 9.20 ± 0.07 log10EID50 0.2 cmE−3, what was provided by infectious doses of 1000–10000 EID50 , which makes it possible to create a virus-containing material with a hemagglutination activity level of 1:64. The size of recombinant vector amplicons expressing proteins ТВ10.4 and ESAT 6 was 1170 bp and 1175 bp, respectively. Electron microscopy images confirm that the developed virions are morphologically similar to the avian influenza virus.