A U.S. federal advisory panel is recommending that all children between the ages of six months and 18 get flu shots.

The current recommendation in the United States is that kids between six months and five years should get the vaccination, along with adults 50 and older, and people with weakened immune systems.

But on Wednesday, the panel, called the Advisory Committee on Immunization Practices (ACIP), said that should be expanded to include children up to age 18. The committee is recommending that the new guidelines take effect no later than the 2009-10 flu season.

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

Dr. Anne Schuchat, director of CDC's National Center for Immunization and Respiratory Diseases says the flu can hit children hard and often leads to them needing intensive medical care.

"This new recommendation should reduce the risk of influenza infections among children of all ages, and their consequent need for medical visits and missed time from school," she said in a statement.

The U.S. has been experiencing a particularly harsh flu season this year, yet Canada has not.

Maps generated by the U.S. Centers CDC show widespread flu activity in 49 U.S. states. Here in Canada, only British Columbia and Ontario have seen widespread activity; the rest are experiencing only localized or sporadic outbreaks.

That's because this year's vaccine is not well matched to the current strains of flu that have been most prevalent in the U.S. The strain most common in the U.S. this year has been a form of the influenza A H3N2 strain that was not included in this year's shot. This year's vaccine has not been well-matched against the predominant form of influenza B circulating in the U.S.

Most of the flu cases in Canada, on the other hand, have been caused by H1N1 viruses. The strains used in this year's shot have been excellent matches with the strains that have predominated here, which may help to explain why we have had a comparatively milder flu season.

In Canada, the National Advisory Committee on Immunization (NACI), the group that advises the Public Health Agency of Canada, currently says that children between the age of six and 24 months should be considered a high priority for the flu vaccine.

But they also recommend that everyone aged 2 to 64 years be encouraged to receive the vaccine, even if they are not considered at high risk of the illness.

The Canadian Paediatric Society, which represents pediatricians in Canada, also recommends that all children over six months old get a flu shot each year, "to prevent illness and reduce spread of influenza to those who are more vulnerable."

They also recommend that all members of households with children younger than two years old should get a flu shot.

"This is especially important if there are children under 6 months old in the home, since babies this age can't get the shot themselves and could become infected if a family member gets the flu," the Society says on its website.