The second generation COVID-19 vaccines should produce the long-term protective immune response to the existing and novel strains of SARS-CoV-2. The Convacell® vaccine was designed to produce such immune response by using N protein as an antigen. N-protein is not susceptible to fast accumulation of mutations and is highly homologous to nucleocapsid proteins of other β-coronaviruses. The study was aimed to perform in vitro assessment of the Convacell® vaccine ability to produce immune response to the Wuhan, Delta, and Omicron strains. Mononuclear cells of vaccinated volunteers and survivors were subjected to N protein stimulation. After that specific activation of the cells was assessed by flow cytometry. The results showed that a sibstantial percentage of CD4 and CD8 cells produced IFNγ and IL2 in response to stimulation. No significant reduction of the response to strains Delta and Omicron compared to the Wuhan strain was revealed. The findings support the direction of the N protein based vaccine design towards creation of the universal vaccine.
The process of production of inactivated influenza vaccines involves a stage of inactivation of both the influenza virus and the possible viral contaminants that can come from the raw materials (chicken embryos). One of such contaminants is the avian leukemia virus. The minimum viral contaminant load reduction that the inactivating agents should guarantee is by 4 lg/ml; this or higher level of the deactivating ability ensures the finished vaccine is free from viral contaminants. The purpose of this work was to cultivate the leukemia virus to the titer of 5 lg/ml (minimum) and to measure the reduction of the avian leukemia virus titer in influenza vaccine intermediates upon exposure to the inactivating agents. The RAV-1 and RAV-2 leukemia virus strains and influenza vaccine intermediates such as virus-containing allantoic fluid and virus concentrates were used in the study. Avian leukemia virus titers were determined by enzyme immunoassay. We created conditions for cultivation of the RAV-1 and RAV-2 avian leukemia virus strains in the primary culture of chicken embryo fibroblasts (CEF); the inactivating agents considered were the most commonly used β-propiolactone and UV radiation. It was found that after 12 hours of exposure to β-propiolactone, the RAV-1 avian leukemia virus load decreased by 4.61 ± 0.46 lg, and that of RAV-2 strain - by 4.33 ± 0.33 lg, which indicates that β-propiolactone is an effective inactivating agent. Five minutes of exposure to UV radiation reduces the RAV-1 strain viral load by 4.22 ± 0.31 lg and RAV-2 strain viral load by 4.44 ± 0.48 lg.
This article offers the possibility of introducing a water route for passenger transport in Saint Petersburg. Potential routes developed on the basis of Anylogic software are presented. The results and experiences of previous projects are evaluated. The time spent on the road is compared for 4 types of transport: automobile, metro, public land and water. Measures are proposed to instill popularity in this type of transport. Keywords: water tram, water passenger transport, Saint Petersburg, aquabus, Anylogic.
Inactivation of influenza virus and other potential contaminants like avian adenoviruses coming from embryonated chicken eggs is a critical step in the production of inactivated influenza vaccines. Inactivation must lead to a guaranteed reduction in contaminant titers by at least 4 lg (PFU)/ml. The aim of this study was to identify an optimum cell line for adenovirus propagation and to estimate a reduction in adenovirus titers in vaccine intermediates after inactivation. In a series of experiments, we identified the optimum conditions and the optimum cell line for the propagation of avian adenovirus (strains CELO and Fontes). The most commonly used inactivation methods were analyzed, including inactivation by β-propiolactone and UV light. Viral titers were measured by plaque assays. After 10 h of inactivation with β-propiolactone, CELO titers fell by 4.12 ± 0.06 lg, whereas Fontes titers, by 4.20 ± 0.19 lg, suggesting that β-propiolactone is an effective inactivating agent. Exposure to UV light led to a reduction in CELO titers by 4.69 ± 0.89 lg and a reduction in Fontes titers by 4.44 ± 1.06 lg after 5 min. N-octyl-β-D-glucopyranoside added at the splitting step reduced CELO titers by 0.93 ± 0.15 lg and Fontes titers by 1.04 ± 0.12 lg, whereas tetradecyltrimethylammonium bromide led to a reduction in CELO and Fontes titers by 1.18 ± 0.17 lg and 1.12 ± 0.38 lg, respectively.
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