THURSDAY, Sept. 15 (HealthDay News) -- Children typically don't die from the flu or its complications. Still, U.S. health officials reported Thursday that 115 kids younger than 18 died from flu-related causes during the one-year period that ended Aug. 31.

And many of the deaths could have been prevented if the children had been vaccinated against the flu, said the officials from the U.S. Centers for Disease Control and Prevention.

In a report in the Sept. 16 issue of the CDC's Morbidity and Mortality Weekly Report, agency officials said the findings highlight the importance of both annual vaccinations and rapid antiviral treatment.

"It's vital that children get vaccinated," Dr. Lyn Finelli, chief of the CDC's Surveillance and Outbreak Response Team, said in an agency news release.

"We know the flu vaccine isn't 100 percent effective, especially not in children with high-risk medical conditions. That's why it's essential that these two medical tools be fully utilized," Finelli added. "Vaccinate first; then use influenza antiviral drugs as a second line of defense against the flu. Right now we aren't fully using the medical tools at our disposal to prevent flu illnesses and deaths in children."

CDC officials pointed out that only 23 percent of the 74 children older than 6 months with a known vaccination history had gotten a flu shot last season, even though it's been recommended since 2008 that all children 6 months of age and older get vaccinated.

The report noted that many people erroneously think that healthy kids can withstand a case of flu. But roughly half of the kids who died during the 2010-2011 flu season had healthy medical histories.

CDC officials said being young is a risk factor for flu-related complications. Forty-six percent of the children who died were younger than 5 years of age and 29 percent were younger than 2 years.

The other half of the children who died had existing medical conditions, such as a neurological disorder, respiratory disease, and congenital heart disease.

The report also noted that only half of the 94 children who died in a hospital or emergency department had been prescribed antiviral drugs. The CDC said it recommends immediate treatment with antivirals.

Dr. Kenneth Bromberg, director of the Vaccine Research Center at The Brooklyn Hospital Center in New York City, said: "Because the rate of death in young children is not as high as with the elderly, the fact that children under 5 die from influenza infection may not be adequately appreciated. Half of the children who died lacked any risk factors so the general notion that you can identify those at risk is flawed. In addition, vaccinating children against influenza protects the whole population, other family members and children who may not be adequately protected against influenza because of their immune status.

"It is clearly the right thing to do for everyone," he added.

Another report in this week's issue of MMWR said there were low levels of flu activity in the United States from May 22 to Sept. 3, 2011, and the circulating strains appear to be a good match for this season's flu vaccine. This season's shot protects against three influenza viruses -- the 2009 influenza A (H1N1) virus, an influenza A (H3N2) virus, and an influenza B virus. These are the same three flu strains that were circulating in 2010-2011 -- and that's just the eighth time in 42 years that such a trend has occurred, the agency said.

"If trends in that report continue we should have a vaccine that will offer good protection against the viruses we expect will circulate this season," Finelli said in the news release.

The CDC added that people should get vaccinated again this season, even if they were vaccinated last year, because immunity diminishes over time.

More information

To learn more about kids and the flu, visit the CDC.