All children ages 6 months to 18 years in this country should receive an influenza shot every year, a federal advisory panel said on Wednesday.

The recommendation expands by about 30 million the number of children who should get annual influenza shots. Current pediatric recommendations call for influenza vaccinations for children ages 6 months toabout 5 years.

In expanding the new upper age limit to 18 years, the aim is to reduce both the time children and parents lose from visits to pediatricians and missing school and the need for antibiotics for complications, said Dr. Anne Schuchat, who directs the disease agency's program onimmunization and respiratory diseases.

An added expected benefit would be indirect- to reduce the number of influenza cases among parents and other household members, and possibly spread to the general community.

The recommendation, which is voluntary, was made by the Advisory Committee on Immunization Practice, which advises the Centers for Disease Control and Prevention in Atlanta. The C.D.C. and its parent, the Department of Health and Human Services, generally follow the advice of the committee, which is composed of vaccine experts from academia and the private sector.

The committee voted unanimously that the expanded immunization should start as soon as possible, but no later than the 2009-10 flu season. The centers expect that the vaccine industry, which made 132 million doses available this year, will be able to produce a sufficient supply in future years.

Every state but one has reported widespread influenza illness this winter. In Florida, activity is regional. Last week, the centers reported that 22 children had died in this influenza season.