(AP) -- Fears of swine flu helped boost vaccination for ordinary seasonal flu last year, with a record 40 percent of adults and children getting the vaccine, federal health officials said Thursday.
The jump was most dramatic in children, but vaccinations also increased in healthy adults under 50, according to Centers for Disease Control and Prevention researchers.
For all ages, the highest seasonal flu vaccination rate previously was about 33 percent, in the 2008-2009 season.
Flu shots have been around since the 1940s. But several things made last fall's campaign unusual:
- Swine flu appeared last spring and was unusually dangerous to children and young adults, prompting more interest in regular flu shots. "We do have the pandemic driving that," said Gary Euler, one of the study's authors.
- Government recommendations kicked in calling for seasonal flu vaccinations for all children.
- Seasonal vaccine was out earlier than usual so manufacturers could focus on the separate swine flu vaccine.
Annual flu shots were recommended for roughly 85 percent of Americans during the vaccination campaign. Those supposed to get the vaccine include children, pregnant women, senior citizens, health care workers and people with chronic health conditions like asthma, diabetes or heart and lung disease.
The researchers looked at vaccinations through January. The results are being published in a CDC publication, Morbidity and Mortality Weekly Report.
People 65 and older had the highest rate, nearly 70 percent. That age group is at highest risk for serious complications from seasonal flu.
The rate for children over 6 months increased by two-thirds, from 24 percent to 40 percent.
The attention on swine flu was a strong motivator for people to get regular flu shots in 2009, but it's not clear if as many people will get vaccinated this year, said Robert Blendon, a Harvard University public health professor who runs polling on public attitudes about flu vaccination.
Health officials "are going to need a high level of campaigning to keep people focused on doing this year after year," he said.
Seasonal vaccine protects against three strains of flu virus. Next fall's vaccine will include swine flu and not be a separate shot.
Hawaii had the highest seasonal vaccination rate, nearly 55 percent. Massachusetts, Rhode Island and Maine were close behind, giving New England the highest rate as a region.
The Southeast is at the bottom of the list; Florida, Georgia, Mississippi and Alabama had rates under 36 percent.
States with the best vaccination rates in 2009 tend to be at the top every year, CDC officials said. New England also has the most vaccinations against swine flu, and the Southeast has the lowest.
This winter was an unusually quiet season for seasonal flu. Experts aren't sure why, but believe it's possible that swine flu - which hit the nation in a large wave in the fall - muscled out the other types of flu viruses.
Explore further: Most US babies get their vaccines, CDC says
More information: CDC report: http://www.cdc.gov/mmwr