Why many Americans are wary of the swine flu vaccine

As the H1N1 flu vaccine begins arriving at clinics around the country this week, Americans are confronting a difficult question: Is the risk of getting the swine flu higher than potential complications from a vaccination?

Most US doctors say the new H1N1 vaccine, though quickly tested, is safe and effective. The biggest problem right now, they say, is making sure there's enough vaccine for everybody who wants a shot.

But as the US embarks on its largest vaccine campaign in history, a number of concerns – including actual effectiveness, its effect on children with asthma, and the use of miniscule amounts of mercury as a preservative in adult doses – are feeding into a growing reluctance by as many two-thirds of all US moms and dads to give their children the shot, according to a recent Consumer Reports survey.

Health experts worry that the pushback could jeopardize the primary aim of government officials: to contain the spread of swine flu in day cares and schools by urging everyone between ages 6 and 24 to get vaccinated.

"Polls are showing that more parents are more concerned about giving their child another vaccination than the child getting seriously ill, and I think that's going to seriously blunt the government's effort to prevent a massive outbreak," says Sonja Gerrard, an epidemiologist at the University of Michigan in Ann Arbor.

The government hopes nearly half of all Americans will get the shots. So far, between 500 and 600 fatalities have been reported in the US, compared with the oft-cited Centers for Disease Control and Prevention (CDC) figure of 36,000 annual fatalities from seasonal flu, primarily among the elderly.

But some critics of the vaccine suggest that the flu shots are not particularly effective in children, and worse, could cause complications in children with asthma. Bill Sardi, a health journalist in San Dimas, Calif., worries that the vaccine could lead to a more virulent strain as the virus is forced, through what he calls "genetic pressure," to mutate.

So deep is the resistance that there have been reports of "flu parties" where parents expose themselves and their children to the flu. Their thinking is that they will strengthen their immune systems – what they see as a sort of natural vaccination.

For its part, the CDC says flu shots can reduce the risk of infection by as much as 70 to 90 percent in primarily healthy adults.

"There's no doubt there's some benefit" to vaccines, William Schaffner, an epidemiologist at Vanderbilt University, told American Medical News earlier this year.

In aggregate, even a small reduction in flu cases could have a huge impact on overall transmission rates across the country, says Dr. Gerrard of the University of Michigan. That is the main reason why the $3 billion vaccination program, despite variations in effectiveness, has become the country's primary strategy to fight the swine flu.

Partly to ease fears about H1N1 vaccination risks, the CDC is for the first time conducting an extensive survey to track side effects from the new H1N1 vaccinations, including effects on those with asthma. Officials hope this will help debunk other popular prejudices, such as the assertion that vaccinations are linked to autism – something that has never been proven scientifically.

"One reason why folks fear vaccines is that they're don't think they're being treated seriously when there are reactions or they think a particular condition might be linked," says Gerrard. "Now when we have a renewed effort towards maintaining an open discussion between people who are taking vaccines and scientists analyzing the data, people will become more comfortable with these public health measures."

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How schools aim to handle swine flu

Click here for a Q & A on what parents can expect to happen at schools.

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