Because of slow production of the swine flu vaccine, public health officials aren't sure how fast Baltimore-area children will be able to get the two doses recommended for protection against the virus.
That's a concern because early monitoring shows that children are being hospitalized and dying from the H1N1 flu at higher rates than from a standard seasonal flu. And Friday, a top U.S. health official called the H1N1 flu "a young person's disease."
Still, experts recommend that children be vaccinated - even if a second dose cannot be scheduled.
"If I had a child less than 10 years of age, I would absolutely give a child one dose. I think one is better than none," said Dr. Karen L. Kotloff, a professor of pediatrics at the University of Maryland School of Medicine.
Early studies of the swine flu vaccine show that children younger than 10 gain more protection from the virus when they receive two doses about three weeks apart. But supplies are coming slowly from the federal government, so local health departments and doctors have been concentrating on getting children and others their first doses.
The officials say even one dose will help children build antibodies in eight to 10 days. And they say there will be enough vaccine for round two, but no one can say exactly when. Providers are advising parents to mark their calendar and seek a second vaccination for children when and wherever they can: a school, a public clinic, a pediatrician's office or a retail outlet.
"At this point we plan to go back and give booster shots to the kids in school, unless we find there is not the need because they got the second dose somewhere else," said Dr. Peter L. Beilenson, Howard County's health officer.
Advice from the U.S. Centers for Disease Control and Prevention is based on preliminary results of trials conducted by the University of Maryland School of Medicine and other academic sites that measured antibody levels after vaccination.
A more definitive recommendation will come as soon as next week, when results are expected to be available from children given the vaccine 21 days before, rather than just eight days, which was the basis for the preliminary results, said Kotloff, who is leading the trials at the school's Center for Vaccine Development.
Kotloff says she thinks the recommendation for two doses of the H1N1 vaccine won't change - that's the same for children who get seasonal flu vaccine for the first time. Their immune systems have never been exposed to this new flu and so they do not have any protection against it.
Kotloff, who is treating children hospitalized with the H1N1 flu at the University of Maryland Hospital for Children, said the emergency room and outpatient clinic are flooded with children sickened from the virus. Given that children are at higher risk for complications from this flu - some 40 percent of children who have died have had no underlying medical conditions - even one vaccination is important.
"We have lots of kids here who have really bad infections," she said. "The number of children who have died in the last month is higher than the number of children who have died in a complete flu season. Most people will have mild illness - we're not trying to scare the public - but we think this is important."
The CDC reports that there have been many millions of cases of pandemic H1N1 flu since the first wave of illnesses in April. And children have been disproportionately affected. Half of the 20,000 hospitalizations and a quarter of the 1,000 deaths have been children.
In a news conference Friday, Dr. Thomas R. Frieden, director of the CDC, called the swine flu "a young person's disease." He said a recent phone survey revealed that one in five children nationwide had flulike symptoms early this month - though they didn't all have swine flu.
"The survey showed that kids get a lot of infections," he said. "That's why it's important to teach them to cover their mouths when they cough and wash their hands."
And it's important to get vaccinated against the H1N1 flu.
Frieden said more than 16 million doses of vaccine have been produced and more than 11 million doses have been ordered by states. He called the vaccine manufacturing technology "antiquated, but tried and true," meaning that the vaccine could be trusted to work, but production was slow and unpredictable.
If children wait more than three or four weeks for a booster, it's not dangerous, officials said. And that's for the nasal spray or the shot. A second vaccination in less time wouldn't offer more protection and getting a second mist so soon is not advised because it's a live virus.
In Baltimore, there has been huge demand for vaccines at the few clinics scheduled for priority groups, said Dr. Anne Bailowitz, the city's acting chief medical officer. Officials are trying to get everyone one vaccination but expect to be able to offer a booster shot in another month to kids.