NEW YORK (Reuters Health) - Nearly half of Americans would get themselves vaccinated against smallpox right now if the vaccine were made available and nearly two-thirds support some type of mass immunization campaign to reduce the threat of any future bioterror attack, according to a new poll.

When asked "If you were offered a vaccination against smallpox now, would you choose to have it or not?," a full 49% of nearly 3,000 adult Americans surveyed answered "yes," according to the results of a Wall Street Journal Online/HarrisInteractive Health-Care Poll, released this week. Of the remainder, 21% said they would not get vaccinated, while 31% answered "not sure."

Smallpox was eradicated worldwide decades ago, with the last US case reported in 1978. But public anxiety surrounding the potential release of smallpox virus by terrorist groups has escalated since the September 11th attacks. At present, government laboratories in US and Russia are known to hold small supplies of smallpox virus for research purposes, but a recent CIA report concluded that covert stores may also be held in France, Iraq and North Korea.

This week, officials in the UK announced that 350 "first-responder" health workers would be immunized against the disease, while in the US the White House is currently reviewing recommendations on mass vaccinations of military personnel.

According the to WSJ/Harris poll, most Americans support some form of mass immunization of civilian populations as well. Forty-two percent of those questioned supported vaccinating "everyone as soon as possible," with the exception of those at increased risk from the vaccine, such as pregnant women. Another 18% thought a more restricted immunization campaign focused on key health workers, paramedics, police and firefighters was a better option, while 5% suggested restricting vaccination to emergency health care workers only. Overall, 65% of US adults appear to support some kind of mass vaccination effort.

Those who do not support mass immunization may take this stance due to fears of complications associated with the smallpox vaccine. However, the poll indicates that many of these fears may be exaggerated. While the real risks associated with vaccination is about one or two deaths per every million immunized, 46% of respondents thought the risks were higher. In fact, one in every ten Americans believes the risk of death from receiving the smallpox vaccine is up to 100 persons per million, according to the poll.

The survey was conducted during the first week of November 2002, among a representative sampling of 2,924 adults nationwide.