Mycoplasma gallisepticum (MG) is the most economically significant mycoplasmal pathogen of poultry. Infections can cause significant economic losses from chronic respiratory disease, reduced feed efficiency, decreased growth and decreased egg production. Despite success in eliminating MG in grand parent stock, it persists in broiler breeders and broilers in many areas. There also continues to be a high incidence of the disease in commercial layers worldwide. The continued presence of MG in commercial poultry indicates that current efforts at eradication, including available vaccines, have not been successful. Inactivated vaccines, while generally effective in protecting against loss of egg production in layers, do not reliably prevent infection or provide consistent protection against respiratory disease. Live attenuated MG vaccines are typically more effective than inactivated vaccines, but they can produce disease and/or impair reproductive function. Thus, there is a need for an improved live MG vaccine strain that is both safe and efficacious as well as stable and non-virulent.

Researchers at the University of Georgia’s Poultry Diagnostic and Research Center developed a new robust attenuated live vaccine for M. gallisepticum. When administered as a live vaccine, this MG strain exhibited the necessary attributes of an effective vaccine. Namely, the strain is avirulent, immunogenic and stable. These attributes indicate that this new vaccine will provide superior performance when compared to existing products. This new vaccine represents a new weapon to combat the economic losses that result from MG infection.

File Number: 1381