Before 2008, HIV-1 subtype A was the predominant genetic variant in the Novosibirsk oblast of Russia as well as in most parts of this country. However, a rapid spread of the recombinant HIV-1 02_AG form has been reported in Novosibirsk since 2009. We have analyzed the genome of the 10.RU.6637 isolate, a HIV-1 02_AG recombinant form, which represents a monophyletic cluster of the HIV-1 variants widespread in this region. Phylogenetic analysis has shown that the Siberian 10.RU.6637 isolate displays the highest sequence identity to the HIV-1 subtype AG forms circulating in Uzbekistan. However, recombination analysis of 10.RU.6637 has demonstrated that this isolate is a recombinant form between HIV-1 subtype A and CRF02_AG, differing in its genetic structure from both the CRF02_AG reference sequences and the Central Asian variants of HIV-1 02_AG.

One of the factors determining a high degree of heterogeneity in the HIV population is recombination-based variation, which leads to the emergence of the virus variants with a mosaic genome. An example is CRF63_02A1, an HIV-1 variant currently spreading in the Siberian region of Russia. To prove that this HIV-1 variant is a new circulating recombinant form that had emerged as a result of repeated recombination between CRF02_AG and subtype A, we have isolated seven full-length HIV genomes and theoretically analyzed them, that is, reconstructed the phylogenetic relationships, determined recombination breakpoints and regions, and compared them with the regions known for CRF02_AG.

The prevalence of HIV infection in different Russian regions is nonuniform. In the Tomsk region (TR), 2020 HIV new infection cases were recorded in 2013, the morbidity having increased 5.9-fold as compared to 2012. In total, 64 blood plasma samples from primary HIV cases have been examined. HIV-specific fragments of the pol gene have been obtained for 61 samples (of protease for 58 and of integrase for 23) and of the env gene V3 region for 40 samples. Phylogenetic analysis of the determined HIV-1 sequences has detected CRF63_02A1 in 55 (90.2%) cases, whereas HIV subtype A1, characteristic of Russia, has been observed in only three (4.9%) patients. Three (4.9%) cases contain CRF63_02A1/A recombinant variants. This article demonstrates that a drastic activation of the epidemic in the Tomsk region is accompanied by a rapid spreading of the recently described HIV-1 CRF63_02A1, which we detected in the Novosibirsk region outbreak of 2008.

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Introduction. The new coronavirus infection, COVID-19, caused by SARS-CoV-2 has reached the scale of a pandemic. Detection of antibodies to SARS-CoV-2 is an aid in the diagnosis of COVID-19, and is also used to assess the immune response to the infection. Since COVID-19 is a new disease, seroconversions and kinetics of antibody to SARS-CoV-2 are not well understood. The aim of the study is to evaluate seroconversions and kinetics of antibodies to SARS-CoV-2 (IgA, IgM, IgG and total) in real clinical practice using test systems of national production. Materials and methods. 327 blood samples obtained from patients with a confirmed diagnosis of COVID-19 with active infection, convalescents and healthy donors were analyzed. Detection of antibodies to SARS-CoV-2 was carried out by enzyme immunoassay method using registered test systems Antigma-A, Antigma-G, Antigma-Screen and an unregistered test system for the detection of class M immunoglobulins. Results. When testing for total antibodies, 50.0% of samples were positive on days 1-7; 89.4% on days 8-14; 96.2% on days 15-45; and 93.3% after the 46th day after disease onset. The earliest seroconversions occurred on the 3rd day; antibodies were detected up to 81 days after the disease onset. Conclusions. The frequency of detecting seroconversions when using test systems of the Antigma series in real clinical practice is comparable to the data published in the world scientific literature and is high enough to use these test systems in the COVID-19 diagnostics.