The complete nucleotide sequence of the H protein gene of seven measles virus (MV) strains, representing three MV genotypes circulating in the UK in recent years, was determined. Compared to the MV vaccine strain Moraten (Mor-v), the divergence of the coded H gene (aal-600) of the seven UK strains was between 1.8% and 2.8%. Representative isolates from each of the genotypes were tested by radio-immunoprecipitation using a panel of H protein-specific MAbs. Different patterns of MAb reactivity were shown between the three genotypes and between the wild-type strains and the vaccine strain. Plaque reduction neutralising antibody titres against strains UK350/94 (genotype I) and UK226/94 (genotype III) were measured in sera from 11 vaccinees. Vaccine derived antibody neutralised both strains and the GMTs were not significantly lower against the wild-type strains than against strain Mor-v.