Because in the 2021-2022 season, it is expected that in the Northern Hemisphere, including on the territory of Ukraine, several strains of the influenza virus of groups A and B will dominate. In general, experts make a forecast for the spread of certain strains of influenza twice a year, based on research data from different parts of the world. Taking into account the prognosis of the dominance of certain strains, vaccines and tests are being developed, including rapid tests for home check for infection.