Preliminary analysis of the epidemiological effectiveness of COVID-19 vaccination in the Saratov Region

ABSTRACT

The new coronavirus infection (COVID-19) caused by the SARS-CoV-2 virus continues to spread rapidly worldwide, despite the increased prevention and treatment measures being taken. Vaccination is one of the most cost-effective and effective methods of preventing infectious diseases in the modern world, including one of the most effective methods of combating COVID-19. Over several centuries of history, vaccination has proven its effectiveness in saving people's lives, reducing the spread of infectious diseases among the population, as well as reducing mortality. The effectiveness of immunization against COVID-19 is an urgent problem at the moment, especially when it comes to vaccination. The aim of the work is to study the effect of vaccination on the incidence of a new coronavirus infection among residents of the Saratov Region. Material and methods. Methods of retrospective epidemiological analysis of trends in the epidemic process COVID-19 were used. The obtained materials were processed using methods of variational statistics (Excel program). The analysis was based on data from daily monitoring of laboratory diagnostic results (more than 1780 thousand PCR diagnostic studies were conducted during the epidemic), COVID-19 cases and deaths, taking into account the coverage of the population with preventive vaccinations. The statistical significance of the differences was assessed according to the Student's criterion. The differences were considered significant at t<=2. Results and discussion. As of June 30, 2021, more than 267 thousand people or 11% of the population of the Saratov region were fully vaccinated against COVID-19. There were no complications after the introduction of vaccines. In the structure of all medical immunobiological preparations that were immunized, the proportion of the vaccine "Gam-COVID-Vac" was 97.88%, "Epivaccorona" - 1.69% and "Covivac" - 0.43%. According to preliminary data, 361 of the vaccinated people were infected with SARS-CoV-2, of which 255 (70.6%) had a mild course of the disease with manifestations of catarrhal syndrome, 84 (23.3%) had community-acquired pneumonia, 22 (6%) had no symptoms of the disease. No deaths have been registered among the vaccinated. The overall incidence of COVID-19 among vaccinated was 0.06%. The incidence rate of COVID-19 among the vaccinated population is 6.025+/-0.15 per 10 thousand people, which is significantly lower (t>2) than among the unvaccinated (103.8+/-0.63 per 10 thousand people), efficiency index - 17.23, epidemiological efficiency coefficient - 94.20% Conclusion. Insufficient coverage of the population of the Saratov Region with vaccination (as of June 30, 2021, 11% were fully vaccinated) does not allow to influence the reduction of the incidence of COVID-19. The high epidemiological effectiveness of COVID-19 vaccination of the adult population with domestic vaccines, including people over 65 years of age, has been revealed.Copyright © 2022 Geotar Media Publishing Group