The expansion, for next year, would mean about 30 million more children could be getting vaccinated - everyone except those with serious egg allergies. If heeded - an unlikely scenario, experts said - it would be one of the largest increases in flu vaccination coverage since the vaccine became in the 1940s.

The Advisory Committee on Immunization Practices said all children should start getting vaccinated as soon as possible, for the 2008-2009 season, while also acknowledging that many doctors have already ordered their supply and might not be able to expand until 2009-2010.

The flu season generally starts in the fall and continues through spring.

The panel's advice is routinely adopted by the Centers for Disease Control and Prevention, which issues guidelines to doctors and hospitals.

Shots were already recommended for those considered to be at highest risk of death or serious illness from the flu, including children 6 months to 5 years, adults 50 and older, and people with weakened immune systems.

Children 5 to 18 get flu at higher rates than other age groups, but they don't tend to get as sick. Of the estimated 36,000 deaths a year attributed to the flu, only 25 to 50 occur in children of that age bracket, CDC officials said.

But youngsters who stay home sick from school also cause parents to stay home, so reducing the illness in this group may cut down on lost workdays, some experts said.

They believe that giving flu shots to more children may also prevent the illness from spreading to adults and the elderly, although studies haven't clearly established that link.

Shots are not the only option. A nasal spray vaccine, FluMist, is approved for healthy people ages 2 to 49.

Panel members waffled a bit on how quickly the recommendations should kick in. Some public-health professionals pushed for the clearest endorsement possible of the vaccine, concerned that the public is losing faith in flu shots because this year's vaccine was not well-matched to circulating viruses.

A few argued that the committee should recommend flu shots for every healthy person, period - rather than adding another set of children now, and perhaps young adults in a few years.

The head of the panel, Dale Morse, asked for a report on universal adult vaccination.

Meanwhile, vaccine-makers said they expected to be able to produce enough doses next season to accommodate an extra 30 million children.

But panel members had concerns about how the doses would be given to so many.

No other vaccine is given to nearly all children every year. Most schools aren't set up to do it, and physicians groups said they weren't sure if doctors were ready to handle a flood of children seeking vaccinations every year.

"This is the only vaccination that pediatricians in my community don't want to have to give," said panel member Carol Baker, a Baylor College of Medicine professor.

She said she still felt the recommendation should go into effect next season. But groups representing pediatricians and family physicians said they wanted more time to plan for a possible crush.

Still, only a fraction of people recommended to get flu vaccinations actually do so.

"We probably will need to have low expectations for coverage in the first few years," said CDC epidemiologist Tomy Fiore.

What Change Would Mean

The recommendation: The Advisory Committee on Immunization Practices voted to update guidelines to recommend that all Americans between 6 months and 18 years of age get the flu vaccine every year.

Difference from now: Current recommendation is for ages 6 months through 59 months (five years).

Who is excluded: Children with serious egg allergies.

When it would take effect: If the Centers for Disease Control and Prevention approve the recommendation, as expected, the panel said children should get the shots next fall, if possible. But it acknowledged that many doctors might not receive expanded supplies until the following season (2009-10).

Podcast about the decision: http://go.philly.com/health