Study: Vaccinating schoolchildren best way to stop flu

WASHINGTON -- New research says the best way to protect society's most vulnerable from the flu is to vaccinate school-age children and their parents.

Children already top the government's priority list for swine-flu shots this year because that influenza strain targets the young. That's unusual, as flu usually is most dangerous to older adults.

But Thursday's study, in the journal Science, said vaccinating students should be a priority every year -- because schoolchildren are influenza's prime spreaders and their parents then are the virus' bridge to the rest of the community. The idea: Inoculating spreaders could create something of a cocoon around the people most at risk of flu-caused death.

The research is "in line with the evidence" that schoolchildren act as flu factories, said epidemiologist John Brownstein of Harvard.

Brownstein has tracked Boston-area influenza cases and found that neighborhoods with the most children are where flu strikes first and worst: Every 1 percent increase in the child population brings a 4 percent increase in adult emergency-room visits.

And just last year, the Centers for Disease Control and Prevention started recommended routine flu vaccination for children of all ages. While shots had long been recommended for babies and preschoolers who are at higher risk for flu complications, healthy school-age children typically spend an achy, sneezy week and bounce back.

The change came as scientists began realizing flu vaccine doesn't work as well in people over 65 -- who account for most of the 36,000 flu-caused deaths each winter -- as it does in the young. While flu vaccine protects 75 percent to 90 percent of young healthy people, some research suggests the protection may plummet to 30 percent among their grandparents.

But excluding other ages from vaccination, like in Medlock's model, would be "obviously a very difficult decision" rather than vaccinating schoolchildren in addition to the usual high-risk groups, Brownstein said.