Its authors say the site analyzes risks and steers people objectively as the country prepares for the threat of biological warfare. But the site's first link is "Why you do NOT need a smallpox vaccination," and the authors say most people are more likely to win the lottery than contract smallpox.

"Most people view the risk of getting smallpox as greater than it actually is," said Parker Small of the university's College of Medicine, who co-authored the site with risk assessment specialist John Paling.

Small and Paling say the site is the first of its kind to try to calculate the risks associated with smallpox. But a federal health spokesman said people would be better off getting the government's advice.

"Education is the only thing we've got to decrease irrational fear," Small said now that Florida officials plan to inoculate 35,000 health workers this month in a first phase of a nationwide preparedness effort.

Florida's plans call for vaccinating 435,000 health and emergency workers by June, and possibly offering shots to millions in the public in January 2004.

Inoculating the public is controversial because the vaccine carries a risk of serious side effects, including death for 1 to 3 in a million who receive it.

The Web site lists six steps to making a decision and a table for calculating risk before and after a terrorist attack might occur.

Factors include whether someone is older than 30 and lives in a large city. The authors agreed with government health officials that people vaccinated during a federal program that ended in 1972 would likely remain protected while assuming terrorists would strike a large city, Small said.

The authors did not consult or seek approval from state or federal health officials before launching the site. Paling said some data came from private research and sometimes differed with official government data.

For example, the authors used a study that said people inoculated within seven days of exposure can avert infection, while the government claim is three days.

A spokesman for the federal department overseeing smallpox preparedness said officials are not opposed to the Web site. But Marc Wolfson of Health and Human Service's emergency preparedness office in Washington recommended people refer to information gathered by the U.S. Centers for Disease Control and Prevention.

"Everybody has a right to post material," Wolfson said. "But the folks down at CDC have a pretty good track record."

Small said the Web site's main point is to get information to people. Most people did not know they could be protected by vaccinations after exposure.

"If people were aware of the facts, it would enable them to make better judgments and allay their anxiety," Small said.

Under a worst-case scenario, someone younger than 30 living in a big city after an attack would have a 1 in 85,000 chance of becoming infected, Small said.

That's about the same odds as being involved in a fatal car crash, the authors said.

For people older than 30 living in a rural area, the odds of being infected would be about 1 in 100 million.

Those odds are four times slimmer than winning the Florida Lotto, according to lottery figures.

The decision should be an individual one, said Small and Paling. Meanwhile, each said they would not receive the vaccine if it is offered next year.

"Right now the risk is zero," Small said. "There has not been a case in 20 years."

Staff writer P. Douglas Filaroski can be reached at (904) 359-4509 or via e-mail at dfilaroskijacksonville.com.