Vaccine interaction and protection against virulent Avian Metapneumovirus (AMPV) challenge after combined administration of Newcastle disease and AMPV live vaccine sto one-day old turkeys

The combined administration of Newcastle Disease (ND) and Avian metapneumovirus (AMPV) live vaccines in turkey hatcheries is advantageous, but compatibility has not yet been experimentally demonstrated. To investigate any possible interference between the two vaccines, AMPV subtype B live vaccine strain VCO3 was given to one-day old turkeys either alone or in combination with two different ND vaccines of the B1 and VG/GA strains. AMPV and NDV post-vaccination shedding and humoral immune response were assessed. Birds were protected from virulent AMPV challenge and differences in clinical signs between groups vaccinated with AMPV vaccine alone or in combination with ND vaccines were not statistically significant. Furthermore there were not interference in vaccines replication in the respiratory tract. Further studies are required to understand if protection after NDV challenge is affected by NDV and AMPV combined vaccination.