Introduction: Lack of comparative studies on efficiency of a broad range of COVID19 vaccines leads to lower levels of adoption and subsequent lower total immunity in several regions, including Republic of Belarus. This clinical study captures and transparently demonstrates varying immunogenic responses to Sputnik V and Sinopharm vaccines. Aim of this study was: to compare the immunogenicity and reactogenicity of Sputnik V (Gam-COVID-Vac), RF and Sinopharm (BBIBP-CorV), PRC vaccines in vaccinated individuals. Materials and Methods: A total of 60 adults participated the study. The immune response after vaccination was assessed using enzyme immunoassay. IgG levels measured in all participants at three time points: before the vaccination, 42 days after the first vaccine dose, and 6 months after the first vaccine dose. The results of the SARS-CoV-2 antibody test is quantified according to the WHO First International Standard (NIBSC code:20/136) and expressed in international units (BAU/ml). Results: The study participants were divided into two groups, where 30 people (50%) were vaccinated with Sputnik V (Gam-COVID-Vac), and 30 people were vaccinated with Sinopharm (BBIBP-CorV), with no gender differences in the groups. The IgG levels at 42 days after the first vaccine dose were: Sputnik V (Gam-COVID-Vac)(42 days): Me=650.4 (642.2-669.4); Sinopharm (BBIBP-CorV)(42 days): Me=376.5 (290.9-526.4); p<0,001). The IgG levels at 6 months after the first vaccine dose were: Sputnik V (Gam-COVID-Vac)(6 months) Me=608.7 (574.6-647.1); Sinopharm (BBIBP-CorV)(6 months): Me=106.3 (78.21-332.4); p<0,001). Reactions after vaccination appeared in 27 vaccinated individuals (45%). Conclusion: The study showed that Sputnik V (Gam-COVID-Vac) vaccine was more immunogenic than Sinopharm (BBIBP-CorV) vaccine. IgG levels in vaccinated individuals who previously recovered from SARS-CoV-2 infection ("hybrid immunity") were higher than in SARS-CoV-2 naive individuals. Reactions after vaccines administration were mild to moderate.

Viruses belonging to the Papillomaviridae family have been isolated from mammals, birds and reptiles. The analysis of the genome structure of more than 240 different types of papillomaviruses has made it possible to better understand their evolutionary path. The existing data indicate that many diverse evolutionary mechanisms have influenced their phylogenetic tree. For more than 400 million years, papillomaviruses have occupied various ecological niches. Niche sorting was followed by extensive periods of host-parasite co-evolution. Adaptation to different host tissues, as well as to changing environmental conditions can explain some features of the members of the Papillomaviridae family, one of which is human papillomavirus (HPV), having an important clinical significance. The study of the driving mechanisms of the evolution will help to change the notions about HPV virulence, character of its spread, epidemiology, as well as the pathogenesis and the course of oncologic diseases caused by it. This review highlights some moments of the evolutionary history of papillomaviruses which created a background for the development of oncogenic features of certain HPV types.

Relevance. Many countries around the world are developing effective vaccines against SARS-CoV-2. The measure of the effectiveness of the vaccination process has traditionally been antibody production. The frequency and intensity of adverse reactions is also an important factor in making a decision regarding a vaccine. This study presents the results of the evaluation of the formation of humoral immunity and the occurrence of reactions in response to the administration of Sputnik V (Gam-COVID-Vac), RF, and Sinopharm (BBIBP-CorV), PRC. Aim. Analyze immunogenicity and reactogenicity of COVID-19 vaccines used in the Republic of Belarus (Sputnik V and Sinopharm). Materials and methods. Evaluation of postvaccination immune response by enzyme immunoassay and differential enzyme immunoassay for class G immunoglobulins to S- and N-proteins SARS-CoV-2. Blood plasma of the study participants was used as biological material. Blood sampling was performed 3 times: immediately before the first vaccine dose, on day 42, and 6 months after the first vaccine dose. To evaluate the frequency and intensity of postvaccination reactions, study participants were questioned. Results. At 42 days after administration of both vaccines, antibody levels are rising, with a significantly higher quantitative IgG count for the Sputnik V vaccine. This trend is also observed 6 months after the first dose of both vaccines, both among those previously infected with SARS-CoV-2 and those without a history of COVID-19. The comparison of Sputnik V and Sinopharm vaccine groups in terms of IgG (BAU/ml) levels to S- and N-proteins revealed a statistically significant difference in IgG levels to S-protein: the Sputnik V vaccine group had significantly higher IgG levels to S-protein than the Sinopharm vaccine group (p = 0.0000196). The incidence of adverse reactions in this study was 45%. All reactions noted were mild to moderate in severity. The most common were soreness and redness at the injection site, elevated body temperature, and a combination of several reactions. The increased body temperature after vaccination was more common among those vaccinated with the Sputnik V vaccine. Conclusion. Compared to Sinopharm, Sputnik V vaccine produces higher antibody level. Adverse reactions were observed in both vaccinated groups. However, significant statistical differences were found with regard to fever in the Sputnik V vaccine group, which occurred more frequently.

Relevance. The first case of COVID-19 was registered in 2019. Several months later, the local outbreak became pandemic. The only way to curb the spread of SARS-CoV-2 infection is mass vaccination that aims to form a herd immunity. The success of vaccination depends on people’s acceptance, which might be problematic. The review summarizes the main barriers to mass vaccination against COVID-19, categorizing people based on their willingness to vaccinate, and pointing out possible areas of work to overcome the barriers listed above. Aim. Analyze the problem of mass rejection of vaccination against COVID-19. Determine possible solutions. Conclusion. The main reason for refusal to vaccinate against COVID-19 is the lack of public awareness about the safety and efficacy of vaccines. This review lists possible approaches to creating a supportive information environment and ways to stimulate citizens to accelerate the rates of mass vaccination.

Objectives: Data comparing the immunogenicity of Sputnik-V and Sinopharm vaccines in seropositive and seronegative groups are lacking. We compared the immunogenicity of Sputnik-V (Gam-COVID-Vac) and Sinopharm (BBIBP-CorV) vaccines in seronegative and seropositive groups. Methods: In total, 60 adults participated the study. The immune response after vaccination was assessed using enzyme immunoassay. IgG levels were measured in all participants at 3 time points: before vaccination, 42 days after the first vaccine dose, and 6 months after the first vaccine dose. The results of the SARS-CoV-2 antibody test were quantified according to the WHO First International Standard and expressed in international units (BAU per mL). Results: The study participants were divided into 2 groups: 30 people (50%) were vaccinated with Sputnik-V (Gam-COVID-Vac) and 30 people (50%) were vaccinated with Sinopharm (BBIBP-CorV). The groups had no difference in sex composition. The highest antibody levels were observed 42 days after vaccination in both the seronegative group (P = .006) and the seropositive group (P < .001). At 6 months after vaccination, the IgG value declined much farther among the seronegative group (P = .003) compared to those who had recovered from COVID-19 before vaccination. However, the “hybrid immunity” generated by the Sputnik-V vaccine had greater strength and duration (P < .001). Conclusions: This study showed that IgG levels in vaccinated individuals who previously recovered from SARS-CoV-2 infection (“hybrid immunity”) were higher than in SARS-CoV-2–naïve individuals. In a comparative part of the study, the Sputnik-V vaccine had greater strength and duration of immune response across the 6-month observation period (P < .001).