Differentiating infected from vaccinated animals, and among virulent prototypes of reovirus

► Vaccine efficiency to avian reovirus is limited due to many variants in the field. ► Sigma C from four avian reovirus genotypes were used in differentiating ELISA (DE). ► In most cases, DE allowed differentiating between infected and vaccinated animals. ► Using DE, the genotype and level of neutralizing antibodies can be determined. ► DE enables adjusting vaccines to the virus variants in the field.