The article notes features of the last epidemic season (2020-2021) in the form of extremely low activity of influenza viruses with SARS-CoV-2 remaining dominant in the etiological structure of acute respiratory viral infections. Presented own data indicating the heterogeneity of SARS-CoV-2 (Alpha, Delta, B.1.1.317, B.1.1.397, B.1.1.523) isolated from hospitalized patients was noted. An increase in the etiological role of bocavirus, alpha-coronavirus and metapneumovirus with a decrease in the frequency of parainfluenza viruses, adenoviruses, rhinoviruses and respiratory syncytial virus was established. An unusual shift of the period of maximum activity of respiratory syncytial virus to the 20th week was noted. Attention is paid to the need during the ongoing pandemic COVID-19 to fully immunize children as part of the National Immunization Calendar, also emphasized the role of mandatory annual vaccination against influenza. It is noted that the maximum protective effect of immunoprophylaxis of influenza acute and recurrent respiratory infections can be achieved with a combination of vaccination with bacterial lysates. The article presents a review of the literature and our data demonstrating the safety, good tolerability, and high clinical and immunological efficiency of polyvalent mechanical bacterial lysate for the prevention of acute and recurrent respiratory infections in children. It is shown that the use of polyvalent mechanical bacterial lysate during the prevaccination period makes it possible to substantially reduce the frequency of intercurrent infections, which reduces the number of temporary medical withdrawals and increases the coverage of vaccinations against influenza in organized groups to 85.1%. The role of trained immunity as one of the possible mechanisms providing nonspecific immunoprophylaxis during influenza vaccination and the use of bacterial lysates is discussed.
