Vaccine shifts rotavirus transmission

ATLANTA, July 17 (UPI) -- Vaccines for rotavirus, which causes diarrhea, have implications for combating illness in the United States and temper epidemics worldwide, U.S. officials say.

The research, published in the journal Science, is based on mathematical modeling that takes into account regional birth rates and predicted vaccination levels and effectiveness.

Lead investigator Umesh D. Parashar of the Centers for Disease Control and Prevention said the model suggests that when 80 percent or more of children in a given population are vaccinated, annual epidemics may occur on a less regular basis and more unvaccinated children will be protected.

Data from 2007-2008, when vaccination first reached appreciable coverage levels in the United States, validate the model's predictions, the researchers said.

"Rotavirus vaccines have rapidly and dramatically reduced hospitalizations and emergency room visits for gastroenteritis in American children," Parashar said in a statement.

"This research not only explains the effects of the U.S. rotavirus vaccination program, but also lays the foundation for understanding the tremendous life-saving benefits of vaccination in the developing world, where more than half a million children die from rotavirus each year."