Analysis of the incidence of influenza and acute upper respiratory tract infections under conditions of routine influenza vaccination

Background . Acute upper respiratory tract infections and influenza, while maintaining high epidemiological, social and economic significance, have a major effect on the public health of countries and individual regions. The aim . To study the impact of influenza vaccination on the manifestations of the epidemic process of influenza and acute upper respiratory tract infections in the Irkutsk region. Materials and methods . Epidemiological analysis of the incidence of acute upper respiratory tract infections and influenza, analysis of influenza mortality and the impact of vaccination on these infections were performed using continuous samples of statistical data from the Directorate of Rospotrebnadzor in the Irkutsk Region for the period of 2003–2022 (forms 2, 5). Results . The intensity of the epidemic process of acute upper respiratory tract infections among the general population, children and adults during the observation period was characterized by an uneven course with a tendency towards increase. The dynamics of the incidence of acute upper respiratory tract infections in children and adults demonstrates multidirectional trends over the compared periods. The incidence of influenza in the general population had a steady downward trend, the decrease rate was –8.4 %. At the same time, there are significant changes in the intensity of the epidemic process in the compared periods. The proportion of adults increased in the structure of cases of acute upper respiratory tract infections, and the proportion of children increased in the structure of cases of influenza. Significant changes in the epidemic seasons of influenza are shown. Since the beginning of routine influenza vaccination in the region, the number of vaccinated people has increased annually – from 23.6 to 61.7 % of the population. Against the background of the influenza vaccination campaign, a statistically significant decrease in the incidence of acute upper respiratory tract infections among the general population and children under 14 years of age was registered (p < 0.01). Conclusion . In the Irkutsk region, the epidemiological disadvantage for the studied infections persists. Increasing the regulated indicators of population coverage with preventive influenza vaccinations (75 % and more) will help reduce the incidence rate.