Efficiency of the NIVGRIP inactivated influenza vaccine applied by oral route: evaluation in a community of pre-school children in the period 1981-84.

The NIVGRIP inactivated influenza vaccine prepared in the "Stefan S. Nicolau" Institute of Virology was administered by oral route to 3-6-year-old children of a preschool community in October 1981, 1982 and 1983. There were no cases of acute respiratory tract infection (ARTI) in the community in the winter seasons of 1981-82, 1982-83 and 1983-84, with the exception of 3 ARTI cases recorded in February 1982 in unvaccinated children. In a similar community where no vaccination had been performed morbidity by ARTI was of 20% in 1982-83 and 12.6% in 1983-84. The efficiency and the advantages of oral influenza vaccination are outlined.