New vaccines have the potential to prevent or temper epidemics of the childhood diarrhea-causing disease rotavirus, protect the unvaccinated and raise the age at which the infection first appears in children, federal researchers reported in a study today.
The findings were based on changing patterns of rotavirus transmission in the
The research, published in the July 17 issue of the journal Science, is based on mathematical modeling that takes into account regional birth rates and predicted vaccination levels and effectiveness. 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
"Rotavirus vaccines have rapidly and dramatically reduced hospitalizations and emergency room visits for gastroenteritis in American children," said investigator Umesh D. Parashar, MBBS, MPH, of the Centers for Disease Control and Prevention's
The study showed for the first time that the timing of rotavirus epidemics is dependent on the birth rate in the population because they are driven by infants who have never been infected before. In the
But with the introduction of two vaccines, the first in 2006, rotavirus outbreaks may become less frequent and less pronounced. They also may make their first appearance in children when they are older than the previous norm of less than 5 years of age, according to the research.
In older children, later onset would likely mean fewer cases and less severity of diarrhea.
The modeling and analysis were done by a team of researchers from the
"When you can observe the immediate effects of vaccination and compare them to what the model predicted, you have a head start on stopping this preventable disease in countries where rotavirus unnecessarily kills hundreds of thousands of children," said Roger I. Glass, MD, PhD, one of the study authors and director of the
Lead author Virginia Pitzer, ScD, of Penn State and the Fogarty Center, said, "Each population is going to have a different demographic makeup, and there may be conditions we cannot predict with certainty, but we believe introducing vaccination in the developing world will decrease the terrible burden of rotavirus."