At least 114 children have died from swine flu complications since the spring, up from 95 reported a week earlier, according to the Centers for Disease Control and Prevention.
Meanwhile, the government has decided to release the last of its stockpile of liquid Tamiflu for children because of reported shortages of the swine flu treatment. Enough to treat some 234,000 children is being released.
"We didn't see a reason to keep it in reserve when we have so much illness in children now," CDC Director Dr. Thomas Frieden said at a news conference.
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The government sent some of the stockpile to states in the spring and more earlier this month. To replenish the supply, the government has ordered more from Tamiflu's manufacturer, Switzerland-based Roche Holdings, he added. But that medicine is not expected to come in until early next year.
Pharmacies are able to convert adult Tamiflu capsules - which are in good supply - to pediatric doses, he added.
Also Friday, the White House said President Barack Obama is frustrated by delays in making enough vaccine for everyone who wants protection from the swine flu.
Press secretary Robert Gibbs said Friday the president is frustrated knowing that thousands of people are waiting in long lines at vaccine clinics around the country only to be turned away because of vaccine shortages.
He said Obama won't be satisfied until everyone who wants a swine flu shot can get one.
The administration initially predicted that 120 million doses of the vaccine would be ready by mid-October. That was later cut to 45 million.
Gibbs said more than 26 million doses are available. He blamed manufacturers for the delays.
The 19 new deaths in children under 18 represent lab-confirmed cases reported in the week ending Oct. 23. The CDC also received three other reports of children dying from flu. Those are also believed to be swine flu fatalities but those cases didn't undergo full lab-testing to confirm that.
The increase probably reflects the rise in illnesses that have been seen in many parts of the country this month, and the numbers are expected to get worse, Frieden said.
In the past two months, health officials have seen more reports of flu hospitalizations in non-elderly people than they normally do in entire six-month flu seasons, he added.
Swine flu is more widespread now than it's ever been, with 48 states now reporting widespread flu activity. The only states without widespread flu are Hawaii and South Carolina.
Except for children, CDC officials do not keep an exact count of all U.S. swine flu deaths, but say the number has surpassed 1,000. They don't have a tally of all swine flu illnesses, either, but say many millions have been at least mildly sickened by the virus since it was first identified in April.
Each year 50 to 100 American children die from complications of seasonal flu, which tends to hit the elderly the hardest. Seasonal flu kills an estimated 36,000 Americans annually.
The swine flu vaccination program that began Oct. 5 is picking up, Frieden said Friday. Initially there were only a trickle of doses, frustrating worried people cross the country. But manufacturers have been releasing more doses, and now nearly 27 million doses are available for shipment, up from 16 million a week ago.
According to preliminary information, about half of those vaccinated so far are children and half are non-elderly adults. A very small percentage are elderly. That's appropriate, because many elderly people seem to have some immunity to the virus and so are not considered a priority group for the limited vaccine doses.
The government determined the high-risk groups include children and young people through age 24, people caring for infants under 6 months, pregnant women and health care workers.