Safety Assessment: a Comparative Analysis of Quantitative Content of Bacterial Endotoxins and Evaluation of Pyrogenicity of the Kazakhstan Vaccine QazCovid-in® against COVID-19.

We measured the levels of bacterial endotoxins in the bulk vaccine product (BVP) and finished vaccine QazCovid-in® and evaluated the effect of aluminum hydroxide (adjuvant) on the results of LAL test and pyrogenicity of samples in vivo (in rabbits receiving intravenous injection into the marginal ear vein). Administration of BVP with LPS resulted in a dose-dependent increase in body temperature in rabbits similar to that caused by LPS alone, which suggests that aluminum hydroxide in the vaccine did not affect the pyrogenic response in rabbits. Moreover, the LAL test showed that the aluminum hydroxide did not hinder LPS activity after serial dilution of samples.

[Selection of conditions for effective inactivation of Pseudopestis avium virus (Paramyxoviridae: Orthoavulovirus: Avian orthoavulovirus 1) for the production of a Newcastle disease vaccine].

INTRODUCTION: Newcastle disease (ND) is classified as especially dangerous pathogen. Its primary source is an infected or recovered bird. The virus shedding begins just in a day after infection, and virus remains in the body for another 2-4 months after the recovery. The complexity of the final elimination of the causative agent of the disease lies in its ability for long-term preservation in the external environment and the possibility of constant circulation in one complex between groups of birds of different sex and age. Therefore, the main element of protecting birds from ND is immunoprophylaxis that is based on vaccines containing an inactivated ND virus (NDV). The aim of the work ‒ is to optimize the parameters of inactivation of the NDV actual strain H with formaldehyde at final concentrations of 0.01, 0.025, 0.05, and 0.1% under temperature conditions of 20 2 and 37 0.5 C. MATERIALS AND METHODS: We used a virus-containing suspension of the NDV strain H with an initial biological activity of 10.75 lg EID50/cm3 grown by cultivation in 10-day-old developing chick embryos. RESULTS: On the 16th day after the administration of the tested suspensions of NDV inactivated at different temperatures and concentrations of the inactivant , the geometric mean titers of antibodies to NDV in sera of vaccinated birds were at least 1 : 63 in the hemagglutination inhibition reaction, indicating that the studied inactivated suspensions were antigenically active. CONCLUSION: The optimal parameters of the inactivation mode (final concentration, temperature and time of inactivation) of the NDV strain H were established. The inactivation process at 37 0.5 C with inactivant concentrations of 0.01, 0.025, 0.05, and 0.1% lasts up to 72, 22, 18, and 12 hours, respectively. The inactivation process at 20 2 C with inactivant concentrations of 0.05 and 0.1% lasts up to 22 and 18 hours, respectively.

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.

Genomic Sequence of the New Attenuated Vaccine Strain Neethling-RIBSP of the Lumpy Skin Disease Virus.

We report here the draft genome sequence of the new attenuated strain Neethling-RIBSP of the lumpy skin disease virus, obtained by sequential and alternating passages in cell culture and developing chicken embryos. Genome sequencing allowed the identification of differentiation markers of the new strain.