ts P1 and P3 genes are responsible for satisfactory level of attenuation of ts-1A2 recombinants bearing H1N1 or H3N2 surface antigens of influenza a virus

• Published in: Virology (New York, N.Y.) Vol. 106; no. 1; pp. 187 - 190
• Main Authors: Massicot, Judith G., Murphy, Brian R., Van Wyke, Kathleen, Huang, Kun-Yen, Chanock, Robert M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.1980
• Subjects: Adult; Electrophoresis, Polyacrylamide Gel; Genes, Viral; Hemagglutinins, Viral - genetics; Humans; Influenza A virus - genetics; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza Vaccines - isolation & purification; Mutation; Neuraminidase - genetics; Recombination, Genetic; RNA Replicase - genetics; Temperature; Vaccines, Attenuated - isolation & purification; Viral Proteins - genetics; Virulence
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/0042-6822(80)90241-X

To produce live, temperature-sensitive (ts) influenza A virus vaccines, the A/Udorn/72- ts-1A2 donor strain, which has is lesions in the genes coding for the P3 and P1 polymerase proteins, was mated with three wild-type viruses: A/Victoria/3/75 (H3N2), A/Alaskal6/77 (H3N2), and A/Hong Kong/123/77 (H1N1). From each mating a vaccine strain was selected which contained the two ts genes from the 1A2 parent and the hemagglutinin and neuraminidase genes from the wild-type parent. The three ts-1A2 recombinant viruses were given to adult seronegative volunteers and each was found to be satisfactorily attenuated. The parental origin of genes in each ts-1A2 recombinant was identified to determine which genes from the A/Udorn/72- ts-1A2 parent were responsible for the attenuation of the wild-type influenza A viruses. Only the ts-1A2 P3 and P1 genes were required to produce a satisfactory level of attenuation of the wild-type viruses for adults.