Source: Michael Fielding, MEATINGPLACE, 3/24/15

USDA scientists have created a vaccine that is effective against infectious laryngotracheitis (ILT) and Newcastle disease (ND) – two of the most economically important infectious diseases of poultry. They cause sickness and death in domestic and commercial poultry as well as in some wild birds throughout the world.

By using reverse genetics technology, Microbiologist Qingzhong Yu at the USDA's Agricultural Research Service's Southeast Poultry Research Laboratory (SEPRL) in Athens, Ga., generated new dual vaccines by inserting a gene from the infectious laryngotracheitis virus (ILTV) into the Newcastle disease virus (NDV) LaSota vaccine strain, which has been used for more than 50 years to protect poultry from ND.

Vaccines were tested in more than 100 1-day-old chickens and 120 3-day-old commercial broilers. All vaccinated birds were protected against both ILTV and NDV challenges. They showed little or no clinical signs and no decrease in body weight gains. Vaccines were found to be stable and safe in chickens of all ages.

According to Yu, the new vaccines are safer than the current live-attenuated ILT vaccines. They can be safely and effectively given by aerosol or drinking water to large chicken populations at a low cost.

Newcastle is a highly contagious disease that affects both domestic and wild birds. Its effects are most notably felt in large aviaries, because of its ability to spread rapidly and cause huge economic losses. The disease has hit endemic status in the past in several countries.

The research was published in the Journal of Virology. To read more about this work in the March 2015 issue of Agricultural Research magazine, click here.