Anti-thimerosal laws vex flu shot planners

Physicians in states that have passed legislation banning vaccines containing the preservative thimerosal are complaining that these laws could undermine the already challenging flu shot process.

"The distribution system right now is broken," said Robert W. Steele, MD, a pediatrician at St. John's Children's Hospital in Springfield, Mo. "This makes it that much more difficult." Missouri's law, which bans such vaccines for children younger than 3 and for pregnant women, goes into effect in April 2007.

Six more states have enacted similar measures. California, New York and Washington also target vaccines for these two groups while Iowa and Delaware set the age limit at 8 years. Illinois' measure mandates a total ban. At least 18 more states and Congress have related proposals on their legislative agendas.

At first glance, the trend seems innocuous.

Several medical groups, such as the American Academy of Pediatrics and the U.S. Public Health Service, have even called for the eventual phase-out of the vaccine preservative. This position was driven by widespread fears -- never substantiated by research -- that thimerosal might have a causal link to neurological problems such as autism, coupled with concerns that these anxieties would reduce the chance that parents would have their children vaccinated.

While studies regarding any such connection continue, the debate surrounding the thimerosal issue is becoming more heated and controversial, with both sides claiming the scientific high ground.

No major review of the scientific evidence has been able to prove a link, but advocates for these state laws argue that they want to ensure that children have access to safe vaccines.

"I just want vaccines to be safer and without a known neurotoxin," said Lynn Redwood, RN, president of the Coalition for Sensible Action For Ending Mercury-Induced Neurological Disorders.

Conversely, though, state medical societies and other public health groups have been lobbying against the laws and raising alarms that the measures will interfere with efforts to expand influenza vaccination.

"[The laws] are not based on science," said Diane Peterson, associate director for immunization projects at the Immunization Action Coalition. "The authors [of these laws] are well-intentioned, but we feel this is misdirected, bad public policy."

Flu shot complications

Most childhood vaccines are made without the preservative. The notable exception is most forms of the flu shot, which has not been considered a childhood vaccine. Only recently have public health officials tried to reach more kids. In February, the Advisory Committee on Immunization Practices placed children ages 2 to 5 on the list of people recommended to receive shots first. This recommendation was added to the existing one to vaccinate infants against flu.

Only about 10% of annual supplies typically are made in single-dose versions without thimerosal, which is added to multidose vials to prevent fungal and bacterial growth. Manufacturers maintain that it is impractical to produce the entire supply or even a significant portion preservative-free because of the flu vaccine's tight time constraints. They also have said they might not be able to meet the demand created by these laws.

"We may not be in a position this year to supply the total need for no-preservative Fluzone vaccine based on the demand that may result from new state legislation," said John Abrams, a Sanofi Pasteur spokesman.

The laws also are likely to make ordering vaccine far more complicated. For example, Roger Baxter, MD, clinical leader of the flu outreach program at Kaiser Permanente in California, had ordered only small amounts of thimerosal-free flu vaccine to cover the patients who demanded it.

Now he has to factor in California's new requirements for pregnant women and for children younger than 3. The measure takes effect in July. So he must determine how to ensure that each of Kaiser Permanente's many clinics has the correct amount of the pediatric preservative-free vaccine for the children, the adult preservative-free vaccine for pregnant women and a thimerosal-containing vaccine for everyone else.

"We are scrambling to be sure we have enough," Dr. Baxter said.

These dictates even might interfere with efforts to immunize the elderly, the traditional prime target for flu shots. While most of the enacted measures include only pregnant women and children, several proposed bills would institute an overall ban.

"I'm not just fighting for our children," said Lujene Clark, president of Nomercury.org, a Missouri-based group lobbying for these initiatives.

In regard to Illinois' thimerosal-ban law already on the books, the state health department has been granted a waiver, so the upcoming flu season should not be affected.

All seven of the state measures include some provision for a waiver or exemption in the event of a public health emergency.

Still, immunization advocates are particularly anxious about new state laws because the slightest distribution hiccup could put a physician in an awkward position. Physicians who have vaccine but the wrong version for a particular patient could be faced with a difficult decision.

"As these laws take effect and if a physician cannot get the thimerosal-free vaccine, what is a physician to do? Not vaccinate? Break the law? It's a terrible, untenable position to put a physician in," said Howard Backer, MD, MPH, chief of the immunization branch of the California Dept. of Health Services.

Although none of these laws includes an enforcement mechanism or penalties, experts worry they could be used as the basis for a lawsuit or to threaten a physician's license.

"If someone wanted to make an example of some doctor, I don't know what the sanction would be, but it could be very uncomfortable for a lot of people," Dr. Backer said.