Trial Data Inactivated Avian Metapneumovirus Vaccines

Inactivated vaccines are used for the vaccination of chickens (layers and breeders) to protect them against infections during the laying period.

The following experiment was carried out in layer chickens in order to evaluate the efficacy of different vaccination programs. An unvaccinated group and a group vaccinated only with a live vaccine were included as controls. Protection was assessed by measuring the presence of a drop in production and the presence of misshapen eggs laid after an intravenous challenge at 27 weeks of age.

Experimental design

* Challenge at 60 weeks

Results

Graph 1: Egg production (%) before and after challenge of layers vaccinated with - live Nobilis Rhino CV vaccine

* Challenge with aMPV at 27 weeks

Graph 2: Egg production (%) before and after challenge of layers vaccinated with Nobilis RT inac vaccine

* Challenge with aMPV at 27 weeks

Graph 3: Egg production (%) before and after challenge of layers vaccinated with - live Nobilis Rhino CV vaccine and Nobilis RT inac

Graph 4: Egg shell faults (%) before and after challenge with aMPV in vaccinated layers

* Challenge with aMPV at 27 weeks

Conclusions

• The vaccination program based on the use of the live (Nobilis Rhino CV) and the inactivated vaccine (Nobilis RT inac) gave the best results in the challenge experiments. The birds were protected against the presence of clinical signs (data not shown) and against egg drop for at least 60 weeks (data not shown).
• The vaccination program based on the use of the inactivated vaccine (Nobilis RT inac) gave enough protection against a drop in production but the birds were not well protected against the presence of clinical signs (data not shown).
• The vaccination program based only on the use of the live (Nobilis Rhino CV) resulted in good protection against clinical signs (data not shown) but in poor protection against a drop in production.