The influenza vaccines developed in the United States since 1940 have been inactivated virus vaccines given by subcutaneous, intradermal, or intramuscular injection. Protection of very high degree has been conferred on vaccinated persons, but no satisfactory solution of many of the problems involved in immunization against influenza has been found. Meanwhile, workers in Russia have concentrated their efforts on live vaccines, with use of attenuated virus strains administered by the respiratory route. Russian vaccines have not previously been tested in the United States. This report presents observations on the responses of 27 volunteers who received live vaccine in the fall of 1958.
Material and Methods
The vaccine used in this study was prepared at the Metchnikov Institute in Moscow and was received through the good offices of the National Institutes of Health. It was a lyophilized suspension of the fourth allantoic passage of the Iksha (A2) strain. When