ATLANTA, Georgia (CNN) -- Federal health officials said Friday that 38 million doses of the H1N1 flu vaccine are available for states to order, 11 million more than a week ago, but the disease continues to affect children disproportionately.
Dr. Anne Schuchat, who head's National Center for Immunization and Respiratory Diseases at the Centers for Disease Control and Prevention, said the pace of vaccine production was picking up.
"We're expecting about 8 million doses to be available in the week ahead, that's if everything goes well," she told reporters.
Earlier in the year, the CDC had predicted that 40 million doses of vaccine would be available by the end of October, but production delays have hampered agency plans.
According to the CDC, 48 states are reporting widespread H1N1 flu activity, the same number as last week.
But pediatric deaths have risen to 129 since the virus first emerged in April, 15 more since the last update on October 31, the agency said.
Children are particularly vulnerable to the virus, health officials have said. Schuchat said that two-thirds of the children who died from H1N1 had an underlying condition that contributed to their illness, such as "severe neurologic problems like cerebral palsy and muscular dystrophy and asthma."
People under age 25 comprise the majority of hospitalizations and 90 percent of the deaths are occurring in people younger than age 65, she said.
That's a "flip-flop from what we see with seasonal flu," where 90 percent of deaths occur in people 65 and older, she said.
Schuchat reiterated that highest-risk groups should be the first to get new supplies of the shots or nasal spray. Those groups are people age six months to 24 years; pregnant women; parents or caretakers of children younger than six months who can't be vaccinated; people 25 to 64 years of age who have chronic illness; and health care workers.
-- CNN's Miriam Falco contributed to this story.
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