Flu vaccine for youths can aid families

UM researchers report fewer cases of flu when children are protected

December 14, 2006|By Dennis O'Brien | Dennis O'Brien,Sun Reporter

With the flu season expected to peak next month, researchers at the University of Maryland School of Medicine reported today that vaccinating schoolchildren against the disease reduces not only their risk but that of their families as well.

The scientists gave nasal spray vaccine to more than 2,000 children ages 5 to 11 in Maryland and three other states at the outset of the 2004 flu season.

During the peak week of that flu season, children who got the vaccine and their families were less likely to contract the flu or come down with flu-like symptoms than those who weren't vaccinated. They also required fewer medications and doctor's visits, the researchers reported.

FOR THE RECORD - An article in yesterday's editions about tests of inhaled flu vaccine on schoolchildren incorrectly reported the role that MedImmune Inc., the manufacturer of the vaccine, played in the study. A company employee designed the study and reviewed results before publication, but was not involved in data collection. THE SUN REGRET THE ERROR

Advocates said the results add to a body of evidence that vaccinating children against the flu is an effective way to protect adults, too.

"We only looked at one week of the flu season, and yet we saw a big difference. To me, that's phenomenal," said Dr. James King, a professor of pediatrics at the University of Maryland and the principal investigator.

The study, published in The New England Journal of Medicine, was funded by MedImmune, the Gaithersburg firm that makes the FluMist vaccine used in the trial. Company employees were also involved in gathering the data.

Still, experts who weren't involved in the research say the results are worth noting, regardless of the funding source.

"It's impressive they were able to measure such an effect, given the numbers they had," said Dr. Neal Halsey, director of the Institute for Vaccine Safety at the Johns Hopkins Bloomberg School of Public Health.

The study was good news for MedImmune, which has been struggling to find a niche for its inhaled vaccine in a market dominated by injections. But an unrelated study, also released yesterday, showed that for adults, flu shots might be more effective than a nasal vaccine.

Flu kills about 36,000 people in the U.S. and hospitalizes about 200,000 each year, according to the Centers for Disease Control and Prevention.

Youngsters with the flu are more contagious than adults and remain contagious longer because their immature immune systems have more trouble fighting the disease, King said. "They're like little transistors that can amplify it," he said.

Meanwhile, health experts here say the 2006-2007 flu season hasn't peaked in Maryland.

Dr. Anne Bailowitz, chief of the child health and immunization bureau in the Baltimore City Health Department, said the city's clinics are attracting about the same numbers as in previous years. But she and others warn that the season doesn't peak until January and February.

They say now is a good time to be vaccinated because it can take up to two weeks for an inoculation to become effective. The CDC recommends flu shots for anyone 6 months or older. FluMist is approved for healthy people ages 5 to 49.

The UM study and others like it demonstrate the wisdom of routinely vaccinating schoolchildren against flu each fall, a procedure now being tested in an unrelated, one-year state program, King said.

The Maryland Department of Health and Mental Hygiene began working with local health departments this school year to provide FluMist to at least 44,000 students since September, according to Greg Reed, program manager for the department's Maryland Center for Immunization.

But the program is funded for only one year. King said that if he can find evidence that it reduced flu cases here, it will bolster his arguments.

"I think the schools are the logical place to turn to," he said, because pediatricians don't have the capacity for mass inoculations.

The notion of immunizing children to protect adults has been studied for years, according to Dr. Dennis Clements, chief medical officer for Duke Children's Hospital.

Research in Texas and other states has shown that when flu begins to spread rapidly, schoolchildren are a primary source. As a result, vaccination programs are starting in Texas, Tennessee and California, according to UM's King.

"There's really no downsides if the vaccine can be delivered in a way parents don't have to take time off work and children don't have to miss school," Bloomberg's Halsey said.

For the UM study, doctors gave FluMist vaccine to 2,717 children in 11 schools in Maryland, Minnesota, Texas and Washington state during October and November of 2004. In 13 similar schools used for comparison, children were not vaccinated.

From follow-up questionnaires sent home in February 2005 -- a week after the peak of the flu season -- researchers learned that vaccinated children and their families experienced 12 percent fewer cases of flu and flu-like symptoms. Although that sounds modest, experts said it would translate into a drastic reduction in flu cases with large-scale vaccination programs.

"Ten or 12 percent of a large population can be a lot of people not getting sick," said Kimberly Thompson, an expert on risk analysis at the Harvard School of Public Health .

In another study in yesterday's New England Journal, University of Michigan researchers found that flu shots marketed by Sanofi Pasteur, a French vaccine maker, were up to 77 percent successful at preventing the flu in adults, while FluMist sprays were up to 57 percent effective.

But experts noted that previous studies have shown that in other settings, FluMist can work better and that both vaccines are generally effective. FluMist contains weakened versions of live flu virus, while Sanofi's flu shot contains killed virus.

"I wouldn't make too much of the differences. I think it just depends on the year and the strain of virus that's out there," Clements said.

dennis.obrien@baltsun.com

Baltimore Sun Articles
|
|
|
Please note the green-lined linked article text has been applied commercially without any involvement from our newsroom editors, reporters or any other editorial staff.