Avian reovirus genotype VI is a newly emerged pathogen causing multiple immune organs damage and arthritic tropisms in chicks

Whole-genome analysis indicated that the σC amino acid sequences of these strains differ significantly from other genotypes and exhibit low conservation. The σC protein of these isolates shares only 48% amino acid identity with the S1133 vaccine strain. Animal challenge experiments confirmed that ARV genotype VI can induce typical clinical signs and pathological lesions in chicks and is highly pathogenic.

Furthermore, inoculation experiments of SPF chicken embryos with the new ARV variant strain have, for the first time, demonstrated that newly hatched chicks develop pronounced symptoms of arthritis, indicating a high risk of vertical transmission. These findings underscore the urgent need to develop updated vaccines that are immunologically matched to emerging ARV variants in order to effectively control avian diseases.