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.

[Genetic stability of the HA, NA, and NS genes of the recombinant vector virus Flu-NS1-124-Omp16 (H5N1) expressing the brucellar gene].

The recombinant strain Flu-NS1-124-Omp16 (H5N1) of the influenza virus expressing the brucellar Omp16 gene was constructed on the basis of the technology of reverse genetics for the purpose of developing vector anti-brucellosis vaccine. The obtained recombinant strain is a genetically stable construction. This stability is confirmed by the comparative analysis of the nucleotide sequences of the HA, NA, and NS genes of the recombinant vector virus Flu-NS1-124-Omp16 (H5N1) expressing the Omp16 gene of the Brucella abortus (GenBank: AAA59360.1). The comparative analysis showed that the nucleotide sequence of the NS gene of the first and the fifth passage level of the Flu-NS1-124-Omp16 (H5N1) virus corresponded for 100% to the initial part of 12AAS2TC_124 Omp16g containing the chimera NS1-124-Omp16 in the composition of DNA (deoxyribonucleic acid) plasmids pHW2000. Total identity with HA and NA genes of the strain A/AstanaRG/6:2/2009 (H5N1) was shown by the comparative analysis of the nucleotide sequences of HA and NA genes of the first and the fifth passage level of the recombinant strain Flu-NS1-124-Omp16 (H5N1). The recombinant vector virus Flu-NS1-124-Omp16 (H5N1) expressing the brucella Omp16 gene maintains the genetic stability during 5 passages in 10-day developing chicken embryos.

Comparative evaluation of effectiveness of IAVchip DNA microarray in influenza A diagnosis.

The paper describes comparative evaluation of IAVchip DNA microarray, reverse transcription PCR (RT-PCR), and real-time RT-PCR versus virus isolation in chicken embryos and shows their diagnostic effectiveness in detection and subtyping of influenza A virus. The tests were evaluated with use of 185 specimens from humans, animals, and birds. IAVchip DNA microarray demonstrates higher diagnostic effectiveness (99.45%) in early influenza A diagnosis as compared to the real-time PCR (98.38%) and RT-PCR (96.22%), thus showing its clear superiority. Diagnostic sensitivity of IAVchip DNA microarray (100%) exceeds the same of RT-PCR (95.95%) and real-time RT-PCR (97.96%) in the range of estimated confidence intervals. IAVchip DNA microarray and real-time RT-PCR displayed equal diagnostic specificity (98.85%), while diagnostic specificity of RT-PCR was 96.40%. IAVchip DNA microarray has an advantage over the other tests for influenza A diagnosis and virus identification as a more rapid method that allows performing simultaneous detection and subtyping of about tens of specimens within one experiment during 8-10 hours. The developed IAVchip DNA microarray is a general test tool that enables identifying simultaneously 16 hemagglutinin (HA) and 9 neuraminidase (NA) subtypes of influenza A virus and also to screen the influenza A viruses from humans, animals, and birds by M and NP genes.