Goatpox virus (G20-LKV) vaccine strain elicits a protective response in cattle against lumpy skin disease at challenge with lumpy skin disease virulent field strain in a comparative study.

In this comparative study, we examine the safety of the sheeppox (SPP) and goatpox (GTP) vaccines and the protective response of these vaccines in cattle against a virulent lumpy skin disease (LSD) field strain. The vaccine safety was tested in rabbits, mice and cattle using ten times recommended dose. In the safety trial, none of the vaccinated animals showed any deviation from physiological norms or fever, inappetence or local/ generalized skin reactions. In the challenge trial, both SPP and GTP vaccine groups developed virus-neutralizing antibodies with an average titre of 2.1 log2 at 21 days post-vaccination. No significant difference in seroconversion was found in cattle vaccinated with SPP and GTP vaccines (P ≥ 0.05). When challenged with a virulent LSD field strain, one animal vaccinated with the SPP Niskhi vaccine strain showed typical LSD skin lesions at the injection sites of different dilutions of the challenge virus. All animals vaccinated with GTP G20-LKV vaccine strain showed full protection. After infection with the challenge virus, unvaccinated fully susceptible control cattle showed characteristic clinical signs of LSD. The average protective index for SPP and GTP vaccine groups was 5.3 ± 1.42 and 5.9 ± 0.00, respectively.

Comparison of Different Methods of Purification and Concentration in Production of Influenza Vaccine.

The overwhelming majority of influenza vaccines are prepared with the use of chicken embryo allantoic fluid. The presence of ovalbumin (this protein constitutes >60% total protein in the allantoic fluid) in the vaccine can lead to severe allergy. Hence, effective reduction of ovalbumin content is of crucial importance for vaccine production. We compared two methods of purification and concentration of influenza virus: zonal gradient ultracentrifugation and combined ultrafiltration/diafiltration and exclusion chromatography protocol, used for fabrication of seasonal vaccines. Combined chromatography is comparable with zonal centrifugation protocol by the results of ovalbumin removal (to meet standard requirements).

Protective immune response of oral rabies vaccine in stray dogs, corsacs and steppe wolves after a single immunization.

In this study the safety and protective immunity of an oral rabies vaccine, based on the live, modified rabies virus strain VRC-RZ2, was examined in stray dogs (Canis Sp.), corsacs (Vulpes corsac) and steppe wolves (Canis lupus campestris). In the safety group (dogs, n=6; corsacs, n=3; wolves, n=3) which was vaccinated with a 10-times field dose/animal, no animals showed any signs of disease or changes in behavior or appetite during the period of clinical observation, similar to the animals in the negative control group. Saliva samples taken from animals prior and post (5th and 10th days) vaccination failed to demonstrate rabies virus antigen. Observations of immunogenicity in vaccinated carnivores (dogs, corsacs and wolves) during a 180 day period showed the titers of virus neutralizing antibodies (VNA) in the blood sera of vaccinated dogs to be within 0.59-1.37 IU/mL. On 14 days post vaccination (dpv), all the wild carnivores had detectable levels of neutralizing antibodies, with mean titers ranging from 0.50 ± 0.07 IU/mL (for wolves) to 0.59 ± 0.10 IU/mL (for corsacs). Weeks after vaccination, all the vaccinated wolves and corsacs had higher levels of neutralizing antibodies: 0.70 ± 0.10 - 0.71 ± 0.08 IU/mL at 30 dpv, 1.06 ± 0.08 - 1.28 ± 0.21 IU/mL at 60 dpv and 0.41 ± 0.09 - 047 ± 0.06 at 180 dpv. The highest level of VNA (˃1.0 IU/ml) was detected at 60 dpv, in all vaccinated animals. After challenge all vaccinated dogs remained healthy for 180 days. Control animals (unvaccinated dogs) developed symptoms of rabies on day 6 post administration of a virulent virus and died of rabies on days 11-13. Of note, the VNA titers in all the wild carnivores (corsacs and wolves) immunized with VRC-RZ2 were higher than 0.5 IU/ml (0.59 ± 0.11 IU/ml), even as early as 14 days post vaccination. These, presumably protective, titers of antibodies to rabies virus were present in the dogs and wild carnivores examined in this study for at least 180 days.

[Technological approaches to development of whole-virion inactivated vaccine from recombinant strain against A/H5N1 influenza in the Republic of Kazakhstan].

AIM: Development of technological stages of preparation of experimental influenza whole-virion inactivated adsorbed vaccine based on recombinant influenza virus strains NIBRG-14 and A/Astana/RG/6:2/2009. MATERIALS AND METHODS: 2 recombinant vaccines influenza strains were used in the study--NIBRG-14 and A/Astana/RG/6:2/2009. Purification of native virus-containing allantoic fluid was performed by ion-exchange chromatography. The virus was inactivated by formaldehyde. Merthiolate at concentration of 0.1 mg/ml was added to the vaccine as a preserving substance. Aluminium hydroxide was used as an adjuvant. Harmlessness and immunogenicity (HI) of the constructed preparation are determining. RESULTS: Virus-containing materials from recombinant strains with biological activity of 8.5 - 9.0 lg EID50/cm3 and hemagglutination activity of 1:256 - 1:1024 in chicken embryos were obtained. Optimal inactivation regimen of non-purified suspensions by formaldehyde was established and combined scheme of purification and concentration of influenza virus was selected that provide harmlessness and immunogenicity of experimental samples of inactivated vaccines against highly pathogenic influenza A/H5N1 in experiments in mice. CONCLUSION: The data obtained on quality parameters of intermediate products and final vaccine give evidence on their compliance with normative parameters for whole-virion influenza purified vaccine.

Comparison of influenza outbreaks in the Republic of Kazakhstan and Russia induced by 2009 yearly new variant of A(H1N1) influenza virus.

The aim of the work is the comparison of the epidemiology of influenza and acute respiratory virus infections (ARVI) in the Republic of Kazakhstan with the corresponding influenza epidemic in Russia induced by influenza pandemic virus A/California/07/2009 in 2009. Data on influenza and ARVI from the Republic of Kazakhstan and Federal Center of influenza was collected and investigated over the course of several weeks from hospitalized patients with the same diagnosis among all population and in age groups on 16 territories of Kazakhstan and in 49 major cities of Russia. The epidemic in Kazakhstan resembled the Russian epidemic in terms of its abnormally early beginning, expression of monoaetiology, the spread of the epidemic into all territories and start of the epidemics among adult population. High percentage of hospitalized people and lethal outcome were registered in this epidemic. Similarity of epidemic process character in corresponding border-line territories of both countries was found out.