Effect of the oral administration of NIVGRIP inactivated influenza vaccine on virus carriage in the nasopharynx of children aged 0-5 years.

The NIVGRIP inactivated influenza vaccine was administered by oral route to 11 children of a semi-closed pre-school community, found to carry viruses in their nasopharynx. Periodic virological investigations demonstrated that after vaccination virus carriage disappeared completely in 7 children; in the remaining 4 cases there was a considerable decrease (from 14 to 6) in the number of virus strains isolated. The virus isolates obtained after vaccination were represented exclusively by enteroviruses (Coxsackie B1 and B3, poliovirus type 1), in contrast with the wider range of viral agents (adeno-, parainfluenza, herpes, Coxsackie, and polioviruses) detected prior to vaccine administration.