By Sam Sholtis
A highly contagious herpes virus causes Marek’s disease, a deadly illness that mainly infects chickens. While it does not make people sick, the virus causes tumors and paralysis in chickens and, if unchecked, can spread rapidly through entire flocks.
Beginning in the 1970s, widespread vaccination for the virus greatly reduced its impact on the poultry industry, but over the years, some strains of the virus have increased in virulence, causing more severe disease and evolving ways to break through and evade vaccine protection. A massive new study by researchers at Penn State and the U.S. Department of Agriculture (USDA), has now identified 10 regions in the virus’s genome that likely played a role in the increases in virulence. The findings could inform the development of next-generation vaccines that are more effective at preventing future breakthroughs, according to the research team.
A paper describing the study published July 29 in the journal Science Advances.
“Even with nearly universal vaccination, Marek’s disease virus still circulates on poultry farms causing losses around the world, across the U.S. and here in Pennsylvania,” said Moriah L. Szpara, professor of biology and of biochemistry and molecular biology in the Eberly College of Science at Penn State and leader of the research team. “We hope that our new study could help inform the design of next-generation vaccines that could potentially stop the virus from evading their protection.”
Co-author Andrew Read, Penn State’s senior vice president for research, started studying the virus on Pennsylvania farms more than a decade ago to try to understand the complex relationship between vaccination, virus transmission and increases in virulence.
Source : psu.edu