Immunogenic and Protective Properties of mRNA Vaccine Encoding Hemagglutinin of Avian Influenza A/H5N8 Virus, Delivered by Lipid Nanoparticles and Needle-Free Jet Injection.

The development of a vaccine against highly pathogenic avian influenza viruses subtype A/H5 is an urgent task due to concerns about its pandemic potential. In this study, we have developed an experimental mRNA vaccine, mRNA-H5, encoding a modified hemagglutinin trimer of influenza virus A/turkey/Stavropol/320-01/2020 (H5N8). BALB/c mice were immunized with the mRNA-H5 vaccine using lipid nanoparticles (LNPs) and needle-free jet injection (JI).

The Immunogenicity of an Artificial Tick-Borne Encephalitis Virus Polyepitope Immunogen May Depend on Spacers Flanking Epitope.

The development of artificial polyepitope immunogens based on the conserved CD4 and CD8 epitopes from different virus proteins combined into a single molecule is a promising approach in the development of vaccines for activating a specific T-cell response. Selection of spacer sequences flanking the epitopes within the construct and providing the optimal processing of such immunogens within the cell is an important step in the design of such vaccines. We report the results of designing polyepitope T-cell immunogens of tick-borne encephalitis virus that differ in the presence or absence of optimally selected alanine spacers between epitopes, as well as the data of comparative analysis of immunogenic properties of DNA vaccines encoding the obtained polyepitope immunogens.

Immunogenicity of DNA Vaccines against COVID-19 That Encode B- and T-Cell Immunogens after Combined Injection.

The possibility of enhancing the immune response to a DNA vaccine encoding an artificial polyepitope T-cell immunogen containing a large number of conserved epitopes from different proteins of SARS-CoV-2 virus (pBSI-COV-Ub) was assessed by additional introduction of a plasmid encoding the secreted receptor-binding domain of the of SARS-CoV-2 S protein (pVAXrbd). Both a specific humoral response and a cellular response of broad specificity were observed in animals co-injected with pBSI-COV-Ub and pVAXrbd. This indicates the potential of this approach as a vaccine strategy.

[Immunization of Mice with the pVAXrbd DNA Vaccine by Jet Injection Induces a Stronger Immune Response and Protection against SARS-CoV-2 Compared to Intramuscular Injection by Syringe].

During the COVID-19 pandemic, it became clear that, to ensure global health security, it is essential to have a developed platform that can be used to develop a safe, low-cost, effective vaccine quickly. DNA vaccines have several advantages over other platforms, including rapid development and ease of production. They are more stable than mRNA vaccines.

[Needle-Free Jet-Delivered mRNA-Vaccine Encoding Influenza A(H1N1)pdm09 Hemagglutinin Protects Mice from Lethal Virus Infection].

Seasonal influenza is an acute respiratory illness caused by the influenza A and B viruses that circulate worldwide. Due to high variability, new strains of the virus emerge every year. Therefore, vaccine formulation has to be revised every year.