Avian metapneumovirus in the USA
An aMPV isolated from a natural outbreak of the disease in Minnesota was adapted to monkey kidney cells (VERO) by serial passages. The 63rd passage was developed into a live commercial vaccine that has been used in the endemic areas in Minnesota and other neighboring states. The vaccine virus infects and replicates in the mucosal lining of the upper respiratory tract and induces an immune response. It is believed that the use of the vaccine and improved biosecurity on the farm has reduced losses associated with the disease caused by aMPV-C infections. Inactivated vaccines have never been used in USA to control aMPV-C disease, unlike elsewhere where inactivated vaccines are routinely used in breeders. Currently, some of the turkey farms in Minnesota and other neighboring states have stopped aMPV-C vaccination and rely on restricted biosecurity to control the disease.
This information is supplied by Dr. Qingzhong Yu.