One of the best examples involves a controversial ingredient present in the H1N1 vaccine: thimerosal. Thimerosal is a form of mercury used in some vaccines as a preservative. Drug makers agreed to phase it out of most vaccines after the U.S. Food and Drug Administration found in 1999 that mercury levels in children who had gotten multiple shots often exceeded safety levels set by the Environmental Protection Agency (EPA). Nonetheless, thimerosal still remains in many flu vaccines.
Controversy has raged for years about whether or not thimerosal is behind soaring childhood autism rates. While that debate continues, a 2008 study in the U.K. journal Toxicological and Environmental Chemistry found that boys who were given a vaccine containing thimerosal were nine times more likely to have developmental problems than unvaccinated boys.
The Public Health Agency of Canada says on its Web site that thimerosal is safe and that the amount in the H1N1 vaccine is below Health Canada’s daily safety limit set for mercury. “There’s significantly less mercury in the vaccine than you would find in a can of tuna fish,” the site states.
In fact, the amount of mercury in the nonadjuvanted H1N1 vaccine does actually exceed the daily safety level for pregnant women. Health Canada has established the safe dietary level of mercury for pregnant women at 0.2 micrograms (millionths of a gram) per kilo of body weight. The nonadjuvanted H1N1 vaccine contains 25 micrograms of mercury.
Simple math tells us an average Canadian pregnant woman—weighing 80 kilograms at term—gets about 56 percent more than the daily safe level of mercury when given a dose of the nonadjuvanted vaccine. By the EPA’s stricter standards, that same dose is actually triple its daily safe level.
What’s more, Shaw notes, those daily safety levels were set for consumption of mercury in food, not for injection directly into the body. Injecting a neurotoxin like mercury has much more impact than eating it, he said.
H1N1 Vaccine. Is it safe?
