Epidemiological effectiveness of domestic influenza vaccines in cases with vaccination against a new coronavirus infection in 2022–2023

The study presents the results of an epidemiological prospective field cohort study on a comparative assessment of the epidemiological effectiveness of domestic inactivated influenza vaccines and vaccines against new coronavirus infection during immunization of adults aged >18 years. Statistically significant differences were found in the incidence of influenza, acute upper respiratory infections, and new coronavirus infection between the vaccinated and unvaccinated groups. The etiologies of cases of acute upper respiratory infections registered in the study participants during the epidemic season of influenza in 2022–2023 were verified. The clinical symptoms of influenza in the vaccinated group were significantly less severe than those in the unvaccinated group. No significant differences were found in the clinical picture of acute upper respiratory infections between the compared groups. Influenza immunoprophylaxis is an urgent problem, which consists of the ability of viruses to change their antigenic structure and avoid immunity, remaining in constant circulation. Thus, the antigenic composition of influenza vaccines must be systematically updated to ensure the formation of effective population immunity. More studies on the etiological spectrum of respiratory pathogens and assessment of the epidemiological effectiveness of vaccination against vaccine-controlled infections in the analyzed groups are needed. Therefore, to assess immunological protection, including the assessment of the epidemiological effectiveness of seasonal vaccines used against influenza and new coronavirus infection, the priority age group includes individuals aged 18–25 years (especially those belonging to organized collectives) and adults with an unfavorable premorbid background. The use of domestic vaccines against influenza and the new coronavirus infection for specific immunoprophylaxis is generally recognized as the most effective sanitary and anti-epidemic (preventive) measure in the morbidity management of several infectious diseases.