The evolution of infectious bronchitis virus is a continuing challenge for the poultry industry. Finding the right combination of vaccines to cross-protect is often critical to success. Sponsored by Poultry Health Today. New, variant strains of infectious bronchitis virus (IBV) will continue to emerge, but their control may depend primarily on strategic vaccination protocols, panellists indicated during an industry roundtable. Mark Jackwood, PhD, University of Georgia, explained “the virus mutates; that’s what it does, and we can’t change that.” He added, “If we do a good job of vaccinating like we’re supposed to, I think it actually helps with keeping the virus from replicating as much.” Common pitfalls that can occur while vaccinating broilers against infectious bronchitis virus (IBV) could derail vaccine effectiveness, panellists cautioned during an industry roundtable. “IBV viruses are fragile, so it’s critical to keep vaccine titers as high as possible, especially when IBV vaccines are applied by spray,” said Kalen Cookson, DVM, Zoetis. “This is why using full doses is important — to preserve as much of the titers as we can before the bird actually sees it and responds,” he said.
A few essential adjustments in the way infectious bronchitis (IB) vaccines are handled and administered at the hatchery can improve vaccine efficacy, Brian Jordan, PhD, University of Georgia told Poultry Health Today. “Frozen vaccines that come out of liquid nitrogen have to have a little bit more care,” Jordan cautioned.
Vectored recombinant herpesvirus of turkey (HVT) vaccines provide greater flexibility and produce long-term immunity, explained Abigail Reith, DVM, Zoetis. “The onset of immunity for Poulvac Procerta HVT-ND is fast-acting, and broilers are fully protected against Newcastle disease by 19 days of age,” she said. “Broilers need live vaccines for protection against other diseases – particularly infectious bronchitis. By using the recombinant instead of a live vaccine when broilers need ND protection, there are fewer reactions,” she added.
Newcastle disease (ND) throughout most of the US remains stable, but the industry needs to be on guard for changes in the virus, warned Guillermo Zavala, DVM, PhD, Avian Health International. “Viruses are starting to slowly change on us, little by little, possibly making it necessary in the future to start adapting vaccines to optimize the protection that they provide,” he said. Source: