Apr. 22, 2010 Attenuated live vaccines that protect poultry
against Newcastle Disease may be altering the genetic makeup of
the wild virus strains, which could make future outbreaks
unpredictable and difficult to tackle, according to biologists.
Newcastle Disease is an economically devastating poultry disease
that costs the industry millions of dollars. "Many vaccines in
the animal industry are developed by modifying a virulent live
virus," said Mary Poss, professor of biology and veterinary and
biomedical sciences, Penn State. "These vaccines elicit a strong
protection against disease." However, vaccinated birds can shed
the vaccine virus to infect other birds, and live virus vaccines
do not always protect birds from infection from other viral
strains of Newcastle disease. Poss and her Penn State colleagues
Yee Ling Chong, graduate student in biology; Abinash Padhi,
post-doctoral fellow and Peter J. Hudson, Willaman professor of
biology, found that one vaccine strain recombined -- exchanged
genetic material