[Pharyngeal viral population in 3- to 6-year-old children before and after influenza immunization using the NIVGRIP vaccine administered orally].

Immunofluorescence techniques were used to investigate the incidence of viral antigens in exfoliated pharyngeal cells collected from 94 3-6-year-old children living in a collectivity, vaccinated by oral route with NIVGRIP inactivated influenza vaccine. The vaccination resulted in a significant decrease of IF-positive subjects from 80% before to 39% after immunization, indicating a fall in the virus carriage level. The percentage of children in which two or more viral antigens were found also decreased from 72% to 33%. As regards the incidence of different viruses, the complete disappearance of influenza antigens and a marked decrease of the other investigated viral agents were recorded.