In Russia, 131,590 cases of hemorrhagic fever with renal syndrome caused by 6 different hantaviruses were reported during 2000–2017. Most cases, 98.4%, were reported in western Russia. The average case-fatality rate was 0.4%, and strong regional differences were seen, depending on the predominant virus type.

Vaccines based on the strain Sofjin of the Far-Eastern tick-borne encephalitis virus (TBEV) subtype have been used for TBE prophylaxis for over 50 years in Russia and neighboring countries. On the wide territory, where all known TBEV subtypes are circulating, the cultural, purified, concentrated, inactivated TBE vaccine Moscow has been shown to be safe and efficacious in a massive immunization. In the present work, we describe the genome of the vaccine strain Sofjin. We have shown that it differs from TBEV strains previously published with the name “Sofjin”. Moreover, we have shown the stability of the virus during the vaccine manufacturing process on the molecular level.

The pandemic caused by the novel betacoronavirus SARS-CoV-2 has already claimed more than 3.5 million lives. Despite the development and use of anti-COVID-19 vaccines, the disease remains a major public health challenge throughout the world. Large-scale screening of the drugs already approved for the treatment of other viral, bacterial, and parasitic infections, as well as autoimmune, oncological, and other diseases is currently underway as part of their repurposing for development of effective therapeutic agents against SARS-CoV-2. In this work, we present the results of a phenotypic screening of libraries of modified heterocyclic bases and 5-norcarbocyclic nucleoside analogs previously synthesized by us. We identified two leading compounds with apparent potential to inhibit SARS-CoV-2 replication and EC50 values in a range of 2070 M. The structures of these compounds can be further optimized to develop an antiviral drug.

Various adjuvant effects on the immunogenicity of the candidate inactivated Puumala virus vaccine were detected in BALB/c mice. Adjuvants under study were: aluminum hydroxide, spherical particles of Tobacco mosaic virus coat protein, B subunit of heat-labile enterotoxin of Escherichia coli, and low endotoxic lipopolysaccharide of Shigella sonnei. Aluminum hydroxide (1 mg/ml) did not affect neutralizing antibodies' induction and vaccine stability during storage compared to immunization with the vaccine without adjuvant. B subunit of heat-labile enterotoxin (0.2 µg/ml), low endotoxic lipopolysaccharide (50 µg/ml), and plant virus-based spherical particles (300 µg/ml) significantly enhance the humoral immune response of vaccine (p < 0.0001). Pronounced stimulation of IL-12 and IFN-ɣ was observed when mice were immunized with vaccines both with adjuvants (except of aluminum hydroxide) and without adjuvants. It has been shown that low endotoxic lipopolysaccharide contributes not only to enhance the immune response but also to stabilize vaccine immunogenicity during at least 1 year storage.