title: Characterization of the genotype and level of attenuation of an influenza A reassortant virus produced by mating the Xia-ts donor virus with A/Beijing/70 (H1N1) wild type virus.
abstract: Two H1N1 progeny viruses derived by mating the attenuated donor virus, the A/Ningxia/72-ts (H3N2), and the A/Beijing/70 (H1N1) wild type virus were characterized for their genotype and their level of attenuation in susceptible adult volunteers. One progeny virus, clone PX62, was not a reassortant since it received each of its eight RNA segments from the H1N1 wild type virus. THis virus caused febrile influenza illness. Another progeny virus, clone PXH107, was a reassortant which received the genes coding for the surface antigens from the H1N1 parent virus but each of the other six RNA segments from the H3N2 parent virus. This clone was satisfactorily attenuated in susceptible adults and induced an immune response in at least 60% of the vaccinees. These results indicate that the genetic determinants of attenuation of the A/Ningxia/72-ts virus reside on one or more of the RNA segments that do not code for the surface antigens.
mesh_terms: D000293:Adolescent; D000328:Adult; D000954:Antigens, Surface / Q000235:genetics; D005815:Genetic Code; D005838:Genotype; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D009980:Influenza A virus / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity; D007252:Influenza Vaccines / Q000276:immunology*; D014613:Vaccines, Attenuated / Q000276:immunology; D014779:Virus Replication
chemical_list: D000954:Antigens, Surface; D007252:Influenza Vaccines; D014613:Vaccines, Attenuated