Isolation of Influenza A Virus from Normal Human Contacts During an Epidemic of Influenza A. ∗

Abstract

Summary

By the direct intra-allantoic inoculation of unfiltered throat washings influenza A virus was isolated from 5 of 13 apparently normal contacts during an epidemic of influenza A. Significant increases in neutralizing antibodies were demonstrated in the sera of 9 of 13 such contacts by means of the red blood cell agglutination inhibition test.