Thimerosal and vaccinations: Ban on mercury in vaccines gets push

But the bill continues to draw fire from flu vaccine manufacturer Aventis Pasteur and the California Conference of Local Health Officers, who worry about the ban creating a vaccine shortage during a major flu outbreak.

"Aventis Pasteur believes this legislation would curtail the access of Californians to needed vaccine and undermine public confidence in one of health care's most effective prevention tools," spokesman Len Lavenda said in a statement.

Parents of autistic children, the California Nurses Association and others support the measure, arguing that it makes no sense to include a mercury-based preservative in vaccines given to developing infants.

The bill, which has passed the Assembly and awaits a vote on the Senate floor, would apply to vaccines for children age 3 and younger and pregnant women.

Many parents of autistic children blame thimerosal for their children's disorder, although some scientists disagree and the cause of autism remains a mystery.

"If there is the slightest whisper that it might be unsafe and toxic ... why not do something about it?" asked actor Gary Cole at a Sacramento news conference Wednesday.

Cole, who plays the vice president on the television show "The West Wing," said his daughter had "a very severe reaction" to a diphtheria, tetanus and pertussis shot at 18 months. Her face swelled so much that her eyes were nearly shut. A short time later, her speech and eye contact began to regress, he said. His daughter, now age 11, has been diagnosed with autism spectrum disorder.

"I have to ask questions because of that," he said.

Rick Rollens, the father of an autistic child and a co-founder of the M.I.N.D. Institute at UC Davis, noted that health officials advise pregnant women not to eat seafood because it may be contaminated with mercury yet don't seem to worry about thimerosal.

"Everyone's been working very hard to reduce the amount of mercury in our bodies," Pavley said. "In an abundance of precaution, I'm carrying this bill because we know alternatives are on the market."

Thimerosal, a compound that is 49.6 percent mercury by weight, has been used as a preservative in some vaccines and other pharmaceutical products since the 1930s. Its purpose is to prevent fungal and bacterial contamination in multidose vials of vaccines.

Thimerosal is made up of ethyl mercury, a different form than the methyl mercury that has triggered widespread government warnings about fish consumption and other types of exposure. Scientists know much less about the potential impact of ethyl mercury.

In 1999, as a precautionary measure, the American Academy of Pediatrics and the U.S. Public Health Service urged drug companies to voluntarily remove thimerosal from children's vaccines.

The recommendation came after the Food and Drug Administration determined that children who received the full set of recommended immunizations could accumulate doses of mercury that exceeded Environmental Protection Agency guidelines.

Today, most childhood vaccines are thimerosal-free. The one exception is the flu vaccine, which is now available with and without thimerosal. Manufacturers produce much greater quantities of the thimerosal version, however.

This year, federal officials added the flu vaccine to the routine childhood immunization schedule. That heightened concerns about thimerosal.