The Internet-based survey of a nationally representative panel of 2,067 U.S. adults took place in early June.
At that time, 49.6% of those surveyed said they were likely to get the H1N1 swine flu vaccine. If they do, it means nearly 115 million U.S. adults will seek the vaccine when it becomes available.
People who get their yearly flu shots were more likely than others to accept the new vaccine, found RAND Corp. researchers Jurgen Maurer, PhD, and colleagues.
However, those ages 18-49 and 50-64 said they were more likely to get the new vaccine than to get their seasonal flu shot. Those over 65 said they were less likely to seek the new vaccine than the seasonal vaccine.
Overall, Americans seem more likely to seek a swine flu shot than to get their seasonal flu vaccination.
But does that mean the cup is half full or half empty? The survey suggests that more than half of Americans will not want a shot -- even if there's plenty of vaccine to go around.
"Our findings ... caution against taking high uptake rates for a potential novel H1N1 vaccine for granted," Maurer and colleagues warn. "Achieving high rates of uptake of novel H1N1 vaccine will likely require a very aggressive and culturally appropriate public information campaign and strong recommendations from health care providers."
The survey findings appear in the September issue of the journal Vaccine.