Toward the end of an intense, six-hour meeting yesterday designed to gauge public support for a major vaccination campaign against swine flu, someone asked how many people had changed their minds - pro or con - based on what they had heard.

Out of 97 people in the room, four hands went up.

It was a telling moment, crystallizing a major challenge for health officials, who believe the new flu could cause widespread illness but who are grappling with how to get that message out to a skeptical public.

In particular, government officials are trying to read how people feel about swine-flu shots. At 10 meetings around the country this month, they are asking people to consider, debate, opine about, and vote on three possible strategies: "go slow" (as with seasonal flu), "full throttle" (stimulate more demand for shots), or something in the middle.

The shots would be voluntary no matter which option is taken, so the notion of stimulating demand rests largely on educating people about what doctors believe are the risks of swine flu and the benefits of the vaccine. Based on yesterday's session at the Crowne Plaza Hotel in Trevose, Bucks County, that might be difficult.

After a continental breakfast and a video about pandemics, vaccines, and the four-month history of the novel H1N1 influenza from a top doctor at the U.S. Centers for Disease Control and Prevention, the floor was opened for questions.

"I don't trust the government," participant Nicole Prosser of Cherry Hill said, earning the most applause. "Something smells like a rat."

Seminar leader Jody Erikson used people's concerns - about side effects, corporate profiteering, the possibility that a voluntary program would slip into a mandate - to move them into smaller groups for discussion: "What do we want to say to the CDC?"

Over at Table 8, the conversation wandered into questions of past vaccine side effects. Tony Clemente tried to focus his six fellow participants.

"Which is going to be riskier? Having your child exposed to the virus, or having your child exposed to the vaccine? Life has risks," said Clemente, 47, of Yardley, who works in health-care marketing.

Pat Paolini, a special-education teacher from Eastampton, had personal concerns about vaccines. There are many ways to prevent illness, she said, among them eating more servings of vegetables. "If the body is healthy, you fight it off," Paolini, 56, said.

Joseph Funk, 68, of Bensalem, director of the Bucks County Division of Health and Human Services, who was participating on his own, supported a full-throttle approach. People who are less informed, poor, or more susceptible to illness "need to be educated so they can make the decision," he said.

At the end of the discussion, only Funk would mount a "full-throttle" vaccine campaign. Another man voted to "go slow." The other five at Table 8 supported an intermediate approach.

So did most of the other groups. After lunch, everyone got electronic clickers for some instant polling with multiple-choice questions designed to get at why they chose which option.

Concern about avoiding vaccine side effects turned out to be the most-common first or second reason for people's votes. Preventing as many swine flu hospitalizations and deaths as possible never rose above third place.

The public-health community sometimes argues that it has been too successful for Americans' own good: Vaccines have wiped out the most dangerous infectious diseases, leaving people more fearful of side effects.

For Michéle Samarya-Timm, a public-health educator in Somerset County, N.J., that might well be true - and, after experiencing what to her was an eye-opening session, it might well be beside the point.

"If there is a part of the population that is not going to get the vaccine, the government should be talking about other things they can do to stay healthy," said Samarya-Timm, who is frustrated that the federal government has not launched a hand-washing campaign.

"Give them what they want as well as what they need," she said after the meeting. "That is public health."

Contact staff writer Don Sapatkin at 215-854-2617 or dsapatkin@phillynews.com.