A study says that if school-age children are vaccinated against flu, it can protect the entire community from the virus.

Researchers led by Dr. W. Paul Glezen at Baylor College of Medicine found that cases of flu reduced by 10-15% in the adult population of that had children being vaccinated, compared to that of not getting the vaccines. Children younger than 5 registered a 6% reduction in flu cases, while those in the ages of 5 to 11 saw an 8% decline in such cases.

Glezen and his team offered live attenuated influenza vaccine, which is a nasal spray, at elementary schools in eastern Bell County, Texas, in the fall and early winter of 2007.

Nearly half of the children were vaccinated and recorded cases of flu infection that season that needed medical help. The study found immunizing the school kids helped everybody except people in the 12-17 age groups. The study appears in the December issue of the Journal of Infectious Diseases."The indirect benefit that we measured was remarkable considering the circumstances," Glezen said.

"The theory is that, for diseases passed from person to person, it is more difficult to maintain the infection when large numbers are immune," wrote Dr. Edward B. Lewin, a pediatrician, in a commentary accompanying the new study. "The more individuals who are immune, the lower the chance that a susceptible person will come into contact with an infectious person."

"School-based clinics will deliver vaccine to the population with the highest infection rates each year," Glezen said. "We would also recommend that employers offer vaccine to their employees in the workplace . . .If vaccine can be delivered early and systematically to the groups most likely to spread the infection in the community, we will make progress."

The study and commentary appear in the December issue of the Journal of Infectious Diseases.