Recent field isolates of measles virus (MV) obtained by using B95-8 cells have been reported not to agglutinate African green monkey red blood cells (AGM-RBC). Vero cell-adapted, plaque-forming strains derived from three field isolates at the third passage in Vero cell cultures (T8Ve-3, T11Ve-3 and N13Ve-3) also exhibited markedly decreased binding activity, as determined by infectivity-absorption and haemadsorption tests. On the other hand, binding activity of the respective strains at the twentieth passage

Based on phylogenetic and restriction fragment length polymorphism analyses of the hemagglutinin and nucleoprotein gene sequences, measles virus strains obtained in western Japan were divided into two types. Type 1 isolates have largely replaced type 2 isolates during the last 10 years in the area surveyed.