| abstract |
A method and resulting temperature sensitive (ts) recombinants which may be produced by modifying wild-type influenza A viruses by utilization of chemically mutagenized donor viruses possessing ts lesions and shut off temperatures in the area 37 DEG -38 DEG C. Such a recombinant virus has been produced that contains the surface H3 antigen of influenza A/Hong Kong/1968 (H3N2) virus and a temperature-sensitive (ts) lesion derived from a ts mutant of influenza A/Great Lakes/1965 (H2N2) virus. Additional donor viruses include influenza A/Hong Kong/1968-ts-1[A], influenza A double recombinant 10B, and influenza A/Hong Kong/1968-ts-1[E]. When utilized as a vaccine, these temperature-sensitive recombinant viruses have the facility to develop only mild symptoms, but the infection induces complete resistant to influenzal disease produced by challenge with a virulent wild-type virus. The temperature-sensitive donor mutant is prepared chemically by growth of the virus in the presence of 5-fluorouracil (5-FU). |