Vaccination Programs for the Prevention of Avian Metapneumovirus Infection
No general rule can be given as the program has to be adapted to the demands of the field situation.
Some considerations have to be taken into account:
- At what age protection is most needed
- Level of maternal immunity (important for some live vaccines)
- Avoidance of interference with other (live) vaccinations.
Aim of vaccination
It is important to establish the purpose of vaccination.
Broilers and meat turkeys – Vaccination is focused on reducing the economic losses caused by aMPV infections as these are reflected in weight loss and general bad performance of the flock.
Layers and (turkey) breeders – The aim of vaccination is to protect the oviduct as infections may result in drops in production and changes in the internal and external quality of the eggs.
Vaccination of young meat turkeys is probably best done in the hatchery, focusing on inducing enough protection so as to cover the whole fattening period. In chickens (will depend on the type of vaccine used) possible interference with IB/ND vaccines should be considered.
In layers and breeders both turkeys and chickens the programs are focused in protecting the oviduct during the production period.
Timing of vaccinations
In general it is recommended to allow four to eight weeks between two live aMPV vaccinations. To allow a good booster effect of the inactivated vaccines preferably 4-6 weeks should elapse between the last live vaccination and the application of the inactivated vaccine.