January 21, 2021

Zoetis US introduces new HVT-IBD vaccine

In a press statement, Zoetis US has expanded its line of recombinant vector vaccines with the launch of Poulvac^® Procerta™ HVT-IBD, which provides early protection against the contemporary infectious bursal disease (IBD) viruses, and Marek's disease, confronting US broilers.

“Poulvac Procerta HVT-IBD is a valuable tool for managing IBD due to the level of protection it provides and because of its early protection against IBD viruses, including the predominant AL2 variant,” says Angela Hartman, PhD, senior principal scientist at Zoetis and project team leader for development of the vaccine.

Kalen Cookson, DVM, director of clinical research, Zoetis, explained that early protection is essential because IBD, which remains a leading disease challenge for the poultry industry, tends to affect younger birds and is highly immunosuppressive.

 “The younger the bird, the more severe the immunosuppression. Immunosuppression may predispose birds to costly secondary infections -a greater concern now that nearly 60% of US flocks are raised without antibiotics,” Cookson explains.

“Maternal antibodies passed from immunised broiler breeders to broilers start to wane at about 14 days of age. Using Poulvac Procerta HVT-IBD closes the gap between passive immunity provided by hens and active immunity initiated by vaccination,” he adds.

In challenge studies, Poulvac Procerta HVT-IBD administered in ovo provided 78% protection at 14 days of age against the AL2 variant, which now accounts for half of the IBD viruses circulating among US broiler flocks.

The Zoetis team also conducted two separate studies to test the in ovo efficacy of Poulvac Procerta HVT-IBD against a classic virulent IBD challenge on day 14 of age. The new vaccine provided 96% protection.

According to Cookson, the vaccine's duration of immunity is at least 63 days of age, which is important because IBD can also cause temporary immunosuppression in older birds. Poulvac Procerta HVT-IBD is therefore expected to be valuable for layers as well as broilers.

The vaccine can be administered in ovo or by subcutaneous injection at hatch.

The backbone of the new vaccine is a turkey herpesvirus (HVT), which is widely known to be safe and protect against Marek's disease (MD), another cause of immunosuppression.

Poulvac Procerta HVT-IBD marks Zoetis' second recombinant vaccine for poultry over the past 12 months. In January 2020, the company introduced Poulvac Procerta HVT-ND, which protects against Marek's disease and Newcastle disease.