Development of a Non-animal-based Vaccine Test for RHDV2
Rabbit hemorrhagic disease is a devastating disease affecting wild, farmed, and companion rabbits. The virus causing the disease is closely related to human norovirus. However, unlike norovirus, which rarely causes severe disease, rabbit hemorrhagic disease causes a syndrome culminating in the death of affected rabbits. The disease was historically not detected in the United States, but in 2020, RHDV2 was isolated from rabbits in Canada and has since caused significant outbreaks and mortality in the United States. While vaccines are available to prevent the disease, USDA licensing of an RHDV2 vaccine requires testing of each lot in live animals to confirm vaccine potency. To provide a non-animal alternative method for testing of a novel RNA-based vaccine, in 2021 NIEHS provided funding to optimize and qualify an in vitro potency assay that uses a monoclonal antibody specific for the RHDV2 target protein. Evaluation of the potency assay will be completed in 2022.