COVID-19 Epidemic in the Kaliningrad Region: Incidence and Infection Control Measures

Introduction: Combating the epidemic of the novel coronavirus disease required decision-making at the state level and joining efforts of medical workers of all specialties. The experience of the Kaliningrad Region deserves special attention since this region is located in Central Europe and the first COVID-19 cases were imported here in March 2020.
Objective: To assess COVID-19 epidemic manifestations and effectiveness of preventive measures at the regional level.
Materials and methods: We performed a retrospective epidemiological analysis of COVID-19 incidence in the Kaliningrad Region from March 2020 to December 2022. All registered cases were confirmed by PCR or immunochromatography assay. The study included 193,259 cases, 1,879 fatal cases, 1,168 samples with the established SARS-CoV-2 genetic variant, and information on 693,627 people vaccinated against COVID-19. The data were analyzed in Microsoft Excel and WinPepi (version 11.65).
Results: In 2020, the COVID-19 incidence rate in the Kaliningrad Region was lower than that in the Russian Federation while in the years 2021 and 2022 the regional rates were, on the opposite, higher than the respective national ones (p < 0.05). All age groups of the population were involved in the outbreak. Periodic rises in the incidence were associated with the replacement of the Delta variant of SARS-CoV-2 with Omicron. We established high efficacy of vaccination against COVID-19: incidence and mortality rates among the unvaccinated were significantly higher than those among vaccinated individuals (p < 0.05).
Conclusion: Organization of uniform infection control measures has enabled timely interdepartmental managerial decision-making to control the epidemic. Russian regions have accumulated unique experience in implementing a set of preventive and anti-epidemic measures to combat the epidemic of the novel infection.

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