Influenza virus antigens in human leukocytes after oral administration of live tissue culture influenza A monovaccine.

: Influenza A virus antigens were detected in leukocytes by immunofluorescence. After intravenous inoculation of the A/Moscow/16/65 (H2N2) vaccine strain to chickens, cytoplasmic antigens of the virus were observed in mononuclear leukocytes from 24 to 72 hours post inoculation (p.i.). The course of antigen detectability was similar after two repeated inoculations of the virus. After oral vaccination of human volunteers with a live tissue culture influenza A monovaccine from the X-47 (H3N2) recombinant viral antigens were also found in mononuclears; the maximal number of antigen-positive cells was observed at 24 hours p.i. The method of membrane immunofluorescence proved to be the most sensitive for antigen detection; it revealed a considerable decrease in the number of antigen-positive cells after repeated administration of the virus to volunteers. This fact may possibly reflect the development of antiviral resistance in the process of vaccination.