Coronavirus infection is a thunderboltfor the wholeworld with a high morbidity and mortality rate among certain age groups. The proportion of cases in Russia is much less in comparison with other countries. The reason for the low susceptibility to SARS-CoV-2 remains a mystery and will be the subject of subsequent discussions. In the article the materials of the studies carried out at the I.I. Mechnikov Research Institute of Vaccines and Sera, concerning the study of adjuvant influenza vaccines are presented. Based on the results of assessment of the molecular and cellular mechanisms induced by various influenza vaccines, an immunological hypothesis is put forward for the influence of nonspecific antiviral effect of mass vaccination using national immunoadjuvant vaccines on the decrease of susceptibility of the Russian population to coronavirus infection SARS-CoV-2.