A new vaccine for Newcastle disease in poultry has been developed by USDA scientists in Athens, Ga. Using reverse genetics technology, the new vaccine is made from part of a virus that is similar to the wild-type Newcastle disease virus circulating in the environment today. Scientists in the agency's Southeast Poultry Research Laboratory developed the vaccine, which not only reduces mortality and severity of NDV symptoms in poultry, but also decreases the amount of virus spread as well.
Researchers found that reverse genetics technology enabled them to generate a new vaccine by exchanging a gene from the original vaccine with a similar gene of the current circulating virus. When the new vaccine, containing gene sequences similar to the wild-type virus, was used in vaccination studies, the vaccinated birds were protected from the disease and shed less of the wild-type virus after infection.
Newcastle Disease affects more than 250 species of birds and typically causes respiratory, gastrointestinal, and/or nervous system symptoms. The most severe form of Newcastle Disease can result in mortality rates exceeding 90% in susceptible chickens. The most recent U.S. outbreak, which occurred in 2002-2003 in California, Nevada and Texas, forced the destruction of more than 3.4 million birds at a cost of $160 million in California alone.