Evidence for serotypic variation among bovine rotaviruses.

Eight field strains of calf rotavirus from the U.K. were compared by neutralisation tests, using convalescent and hyperimmune antisera. Seven of these strains cross-reacted and were considered to be of one serotype, while the 8th was distinguished by a greater than 20-fold two-way difference in neutralisation titre suggesting a second serotype. Three widely-distributed reference strains (U.K., Northern Ireland and Lincoln) cross-reacted with the strains in the dominant serotype, as did 33 of 42 other field calf rotavirus strains. Nine field strains failed to cross-react with either serotype, suggesting the existence of other potential serotypes in the calf population.