Dynamics of interferon in the rhinopharyngeal secretions of adults vaccinated with the NIVGRIP inactivated influenza vaccine by the nasal route

: The study of the kinetics of interferon in the nasopharyngeal secretions (NPS) of adults vaccinated by intranasal route with the NIVGRIP inactivated influenza vaccine and of unvaccinated controls led to the following observations: the large variety of the individual reactions to the IFN inducing action of the NIVGRIPR vaccine: the presence of low titers of a "physiological" IFN in the NPS of 26% of the patients before vaccination; a positive conversion to IFN in 60% of the patients after the first and in 33% after the second administration of the vaccine. No changes were noted in the percentage of IFN positive controls during the observation period. A "physiological" IFN was detected in the NPS of 10% of the controls.