Innoculation Misinformation

Summary
Wild rumors are flying about the newly developed vaccine for pandemic influenza H1N1, also known as "swine flu." We've seen e-mails stating that the vaccine is tainted with antifreeze or Agent Orange, causes Gulf War syndrome, or has killed U.S. Navy sailors. One says the vaccine is an "evil depopulation scheme." The claims are nearly pure bunk, with only trace amounts of fact.

If you are the sort who trusts anonymous e-mails more than you do doctors and experts from the U.S. Centers for Disease Control and the U.S. Food and Drug Administration, you may wish to stop reading now. For others, here are the facts as stated by the best authorities we can find:

• The vaccine does have some risks – the same risks as the seasonal flu vaccine. Except for the virus, it is functionally identical to the vaccine that's given every year.
• The multidose formulation of the vaccine contains thimerosal, which prevents contamination. Some have accused thimerosal of causing developmental disorders in children, but scientific evidence doesn't support this.
• The vaccine does not contain squalene, which has been accused – also without good evidence – of causing Gulf War syndrome.
• There's no reason to believe that a vaccination would cause Guillain-Barre syndrome. GBS was associated with several hundred flu vaccinations in 1976, but there's been no evidence of an association since then, despite close monitoring.
• While it's true that a Navy vessel was prevented from deploying because of a flu outbreak, that had nothing to do with the vaccine, which hadn't been developed at the time. And there were no deaths aboard the ship, as some e-mails claim.
• Vaccination is not mandatory for the public nationally or in any state, although New York requires that health care providers get vaccinated. Massachusetts legislation granting standby powers in case of health emergencies does not require vaccination or establish quarantine "camps."

Analysis
We're starting to feel nostalgic for the early days of the swine flu pandemic, when the rumors centered around devastated villages and zombies in Cambodia. The crop of falsehoods about the H1N1 vaccine, though, are potentially much more dangerous, since they encourage the credulous to avoid vaccination at all costs. These myths fall into two loose categories: claims that the vaccine is tainted or dangerous, and claims that the government is going to make it mandatory anyway and punish anyone who doesn't get vaccinated.

Same As It Ever Was. Really.
"Their EVIL DEPOPULATION plan is in full swing! Do the right thing…get this story out. The seasonal flu shot ALSO contains H1N! and H3N2 and one other deadly flu. DO NOT TAKE ANY VACCINE. NONE…NONE…NONE."

"I've seen a number of stories claiming that the upcoming swine flu vaccine is so dangerous that even the scientists who developed it refuse to get it and tell their families and friends not to get it. The claims seem to stem from fear that this is the same vaccine that was used in the 1976 swine flu outbreak that resulted in a nuerological disorder that caused paralysis and death."

The e-rumors claim generally that the vaccine is dangerous; one even claims it's a government "depopulation" plot. We'll say it straight out: There are some real risks to the H1N1 vaccine. There's nothing shady or secretive about them, though – they're exactly the same as the risks of the seasonal flu vaccines. They're mentioned on the Department of Health and Human Services Flu.gov Web site, the Centers for Disease Control's Web site and the package inserts for the vaccines. People who have previously contracted Guillain-Barre syndrome within six weeks of a vaccination shouldn't get the vaccine. People who are hypersensitive to egg protein may want to avoid it because it is grown in eggs. Pregnant women should get the injection, which is made from killed virus, but should not get the nasal spray, which contains live but weakened virus. And, as with the regular seasonal flu vaccine, there's some chance of side effects, ranging from redness around the injection site to allergic reactions. The CDC and the Food and Drug Administration are monitoring for other adverse effects.

In fact, everything about the vaccine is just like the seasonal flu shot, which has been administered to hundreds of millions of people. "It's a new virus, but the vaccine is made the exact same way," Dr. Bruce Gellin, director of the National Vaccine Program Office at HHS, told us. The regular seasonal flu vaccine is a mix of the three viruses experts predict will be most likely to cause problems in a given year. But it's only an accident of timing that H1N1 is not included in this year's batches of regular flu vaccine. Had the H1N1 virus shown up several months earlier, Gellin told us, it's "very likely" that it would have been a component of the seasonal vaccine. Instead, there's a separate H1N1 vaccine, but it's otherwise no different. And just like the seasonal flu vaccine, it's been clinically tested and approved by the FDA.

Thimerosal
"I keep hearing the swine flu vaccine has a lot of bad stuff in it such as mercury and anti-freeze to name a few."

"Flu shots contain formaldehyde, a known carcinogen, and all multi-dose flu shot vials have thimerosal, (mercury), a controversial ingredient linked to autism."

"Please help in calling the US Food and Drug Administration to discontinue the distribution of the multi-dose H1N1 vaccine with Thimerosal until further evaluation of the current scientific data on the toxicity of Thimerosal additive. This compound is an organo-mercury compound that had been discontinued as vaccine additive in Europe because of its association to Autism and other neurological disorders."

A common theme in the scare stories is that the vaccine contains harmful ingredients. The "tainted vaccine" rumors aren't new to swine flu vaccine – they're old suspicions about vaccinations writ large, pinned to the most recent public health concern. Most of the problems posited with the H1N1 vaccine originated with other vaccines and date back as much as 30 years.

For instance, we've heard from people concerned about the vaccine containing thimerosal, a preservative that contains mercury and that has long been the subject of suspicion without a lot of scientific support. FDA regulations prevent adding thimerosal to primarily pediatric vaccines. The H1N1 vaccine is not specifically formulated for children, and the multidose version – but not the single-dose version – does contain thimerosal. However, the CDC stresses that even flu vaccines with thimerosal should pose no danger to children.

The thimerosal anxiety stems from the fact that it contains ethyl mercury, which is related to the type of mercury (methyl mercury) that can be harmful in food. Thimerosal was removed from pediatric vaccines mainly as a precautionary measure – a 1999 FDA review found that most children's mercury exposure from thimerosal-containing vaccines would be well within the guidelines for methyl mercury, and ethyl mercury may be less likely to affect the brain, especially in the dosage one would get from a vaccine. But the move to phase out thimerosal piqued concern from some parents and activists, who posited a link between mercury in vaccines and developmental disorders like autism.

A 2001 report by the Institute of Medicine found that the idea that thimerosal exposure could lead to developmental disorders was "biologically plausible" but "is not established and rests on incomplete and indirect information." A 2004 report went a step further and recommended rejecting the hypothesis that thimerosal caused autism. The biological mechanism that would account for the causal connection is theoretically possible, IOM said – but only theoretically. Numerous other studies also find no link between thimerosal and developmental disorders. Ironically, thimerosal is added to vaccines to keep them from being tainted. Multidose vaccines require repeated needle insertions, which can push bacteria into the vial. Thimerosal prevents bacterial contamination of vaccines, which can cause illness and toxic shock.