The paper presents the results of the first Russian experience in evaluating the sensitivity of the epidemic and pandemic influenza virus strains, circulating in the period 2009-2010, to the anti-neuraminidase drug zanamivir. A complex of studies, including enzyme immunoassay, fluorometric assay and partial sequence of the neuraminidases (NA1 and NA2) from influenza A virus strain, was applied. The findings Indicate that all the test strains, including those resistant to oseltamivir, were susceptible to zanamivir. The latter is recommended by the WHO for the prevention and treatment of influenza in pregnant women.