The panel voted to expand annual flu shots to virtually all children except infants younger than 6 months and those with serious egg allergies.
That means about 30 million more children could be getting vaccinated. If heeded, it would be one of the largest expansions in flu vaccination coverage in U.S. history. The flu vaccine has been available since the 1940s.
The Advisory Committee on Immunization Practices said all children should start getting vaccinated as soon as possible, acknowledging that many doctors have already ordered their vaccine for the 2008-2009 season and may not be able to give the shots 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 vaccination guidelines to doctors and hospitals.
Flu shots were already recommended for those considered to be at highest risk of death or serious illness from the flu, including children ages 6 months to 5 years, adults 50 and older, and people with weakened immune systems.
The panel said that should be expanded to include children up to age 18.
Children ages 5 to 18 get flu at higher rates than other age groups, but they don't tend to get as sick. Of the 36,000 estimated annual deaths attributed to the flu, only 25 to 50 occur in children in that age bracket, CDC officials said.
But children who stay home sick from school cause parents to stay home, so reducing the illness in this group should cut down days of lost work, some experts said.
Experts believe 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 will happen.
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 whether to make the recommendations kick in immediately. Some public health professionals pushed them to make the clearest endorsement possible of the flu vaccine, concerned that the public is losing faith in flu shots because this year's vaccine was not well matched to circulating viruses.
Indeed, a few argued that the committee should recommend flu shots for every healthy person, rather than adding another set of children now and maybe young adults in a few years.
"Creeping incrementalism, I believe, continues to foster confusion" about who should get the shot and how important it is, said Gregory Poland, a Mayo Clinic infectious diseases expert.
The head of the panel, Dale Morse, asked for a report on universal vaccination of adults.
Meanwhile, vaccine makers said they expect 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.
There's no other vaccine that's given to nearly all kids 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 Carol Baker, a Baylor College of Medicine professor who sits on the panel.
Baker said she still felt the recommendation should go into effect for the next flu season. But groups representing pediatricians and family physicians said they wanted more time to plan for a possible crush.
Maybe they shouldn't worry. Some experts noted that only a fraction of people recommended to get flu vaccinations actually go through with it.
"We probably will need to have low expectations for coverage in the first few years of implementation" of the ages 5-through-18 recommendation, said Tomy Fiore, a CDC epidemiologist.
Before the vote, the panel heard a presentation of a study that found the vaccine was 75 percent effective in preventing hospitalizations from the flu in children 6 months to 23 months.
"We haven't had data showing prevention of severe outcomes like that in that age group before," Fiore said.