Antigenic variation between human respiratory syncytial virus isolates.

Three hybridoma antibodies, prepared against the RSN-2 strain of human respiratory syncytial (RS) virus, have been used to identify antigenic variation between 41 isolates of RS virus collected from widely separated geographical regions over a period of 29 years. One antibody was directed against an antigenic site on the virus fusion protein, VP70. This site was shared by 21 virus isolates tested and its recognition by the antibody was sensitive to the presence of 2-mercaptoethanol. The remaining two antibodies used react against the virus phosphoprotein, VPP32. Two independent sites were recognized on VPP32 by these antibodies. One antibody reacted with all of the virus isolates screened while the second reacted with only 21 out of the 41 virus isolates. On the basis of the variable epitope, two antigenic types of human RS virus were identified. The distribution of each antigenic group among 28 RS virus isolates from the Grampian Region, north-east Scotland, collected between 1982 and 1984 was determined. The reactivity of these antibodies was examined using immunofluorescence staining and by immunoblotting; the latter technique also revealed that the electrophoretic mobility of VPP32 varied in parallel with the variable antigenic site.