You asked for information on legislation in California, Delaware, Illinois, Missouri, New York, and Washington requiring the administration of thimerosal-free (mercury) vaccines to pregnant women and young children. You also wanted to know what benefits are associated with using these vaccines.

SUMMARY

Thimerosal is a mercury-based preservative used in several multi-dose vaccines since the 1930's to protect the vaccine from outside contamination.

Parents and advocacy groups have raised concerns about the risk of autism and other neurodevelopmental problems from mercury exposure in vaccines. But, several scientific studies, including those conducted by the federal Food and Drug Administration (FDA) and Institute of Medicine (IOM), have found no evidence of any adverse effects from exposure to low doses of thimerosal in vaccines.

According to the FDA, manufacturers and government agencies have worked to reduce or eliminate thimerosal from vaccines because of increased awareness of the theoretical possibility of toxicity from low levels of mercury exposure and an increased number of thimerosal-containing vaccines in the infant immunization schedule. Since 2001, thimerosal has been removed or reduced to trace amounts (less than one microgram per dose) in all routinely recommended childhood vaccines, except for some flu vaccines. Thimerosal-free flu vaccines are available in limited quantities for infants, children, and pregnant women.

As a precautionary measure, some states, including California, Delaware, Illinois, Missouri, New York, and Washington, have enacted legislation requiring the administration of vaccines containing no, or trace amounts of, thimerosal to infants, children, and pregnant women. Delaware and Illinois require the use of thimerosal-free vaccines; California, Missouri, New York, and Washington require vaccines to contain no more than trace amounts. Each state allows its health department to temporarily use thimerosal-containing vaccines if there is a public health emergency or vaccine shortage.

In addition, in 2009 Congress considered, but did not pass, legislation (H.R. 2617) that would have banned the administration of mercury containing vaccines to pregnant women and children under age six with certain exceptions.

THIMEROSAL

Thimerosal is a preservative used since the 1930's in several multi-dose vaccines to protect the vaccine from outside contamination. It contains approximately 49% ethylmercury, a form of mercury that studies have shown is broken down and eliminated from the body faster than the form found naturally in the environment (methylmercury).

According to the Centers for Disease Control (CDC), since 2001 thimerosal has been eliminated or reduced to trace amounts in all routinely recommended childhood vaccines, except for some flu vaccines. Thimerosal-free flu vaccines are available in limited quantities for infants, children, and pregnant women.

RISKS ASSOCIATED WITH VACCINES CONTAINING THIMEROSAL

Parents and advocacy groups have raised concerns about the adverse effects of mercury exposure in vaccines. Specifically, many suspect a link between mercury exposure and autism and other neurodevelopmental disorders. However, several scientific studies have found no evidence that low doses of thimerosal in vaccines increase the risk of developing autism or any other behavior disorder. For example, a 1999 comprehensive FDA review of the use of thimerosal in childhood vaccines found no adverse effects other than local hypersentivity reactions. In addition, the IOM's Immunization Safety Review Committee's 2004 final

report found no causal link between thimerosal-containing vaccines and autism. Research into the possible health effects from thimerosal exposure in vaccines is ongoing.

Although the scientific evidence has demonstrated no adverse health risks, in 1999 the American Academy of Pediatrics and U.S. Public Health Service agencies (FDA, National Institutes of Health, CDC, and Health Resources and Services Administration) called for vaccine manufacturers to reduce or eliminate thimerosal from vaccines as a precautionary measure. This policy shift stemmed from (1) an increased awareness of the theoretical potential of adverse health effects from the vaccines, (2) an increased number of thimerosal-containing vaccines in the infant immunization schedule that could result in a cumulative dose of mercury exceeding federal guidelines, and (3) a desire to prevent pregnant women and parents of young children from avoiding vaccination due to safety concerns.

LEGISLATION IN OTHER STATES

Several states, including California, Delaware, Illinois, Missouri, New York, and Washington have passed legislation requiring vaccines with no or trace amounts of thimerosal for infants, children, and pregnant women.

California

California law prohibits the administration of vaccines or injections to (knowingly) pregnant women and children under age three that contain more than 0.5 micrograms of mercury per 0.5 milliliter dose unless it is a flu vaccine, which may contain up to 1.0 micrograms of mercury per 0.5 milliliter dose.

The state health and human services secretary may exempt the use of these vaccines if the secretary and the governor determine there is an actual or potential terrorist threat or public health emergency, including an epidemic or vaccine shortage. By law, such an exemption must meet the following conditions:

1. it expires after 12 months;

2. the secretary and governor must notify the legislature within 48 hours of the exemption and the secretary's findings justifying its approval;

3. upon request, the secretary must notify all interested parties when an exemption is requested;

4. within seven days of issuing an exemption, the secretary must notify all interested parties who have submitted a written request; and

5. the exemption may be renewed for another 12-months for the same incident if the secretary and governor deem it necessary, and the legislature and interested parties are notified (17 California Health and Safety Code § 124172).

Delaware

Delaware law prohibits the administration of mercury-containing vaccines to pregnant women and children under age eight unless the state health and social services director:

1. is informed that an FDA-approved mercury-free vaccine is not available for any of these groups, in a medically necessary period;

2. determines that there is an emergency or epidemic requiring the their vaccination; or

3. determines there is a mercury-free vaccine shortage that could threaten the health of these groups and in any of these cases additional vaccines cannot be manufactured or obtained from any other source within the medically necessary period;

If the director authorizes the use of mercury-containing vaccines for pregnant woman and children under age eight under any of these situations, he or she must post it on the health and social service department's website within 72 hours of making the determination. The posting must include the specific disease, vaccine, and period for which the mercury-containing vaccine is approved.

The law requires a person administering a mercury-containing vaccine to a pregnant woman or child to inform either the pregnant women or the child's parent or legal guardian that the (1) vaccine contains mercury, (2) vaccine administrator believes it to be medically necessary, and (3) health and social services director has made a formal determination that it may be administered. If a child's parent or legal guardian is unavailable during the period deemed medically necessary, he or she must be informed in writing as soon as possible (16 Delaware Code § 510).

The law was enacted January 1, 2006 and amended in 2007 to require the administration of mercury-free vaccines rather than those with trace amounts.

Illinois

The legislature enacted the “Mercury-Free Vaccine Act” (PA 94-614) in 2005. The act phased out the use of mercury-containing vaccines by January 1, 2008. The law, with certain exemptions, prohibits the administration of a vaccine or injection containing mercury to anyone. It requires the Illinois Department of Public Health (IDPH) to implement a policy to preferentially distribute thimerosal-free flu vaccines to children under age three who are participating in the state's Vaccines for Children program as long as such distribution does not impede health care providers' vaccine supply.

The law allows IDPH to exempt the use of mercury-free vaccines if the department determines there is an actual or potential (1) bioterrorism incident; (2) public health emergency, including an epidemic; or (3) shortage of mercury-free vaccine at a reasonable cost that would prevent a person from receiving it. Within 48 hours of issuing the exemption, IDPH must notify the legislature and explain its decision. This exemption expires after 12 months, but may be renewed if the same incident or public health emergency remains. Upon request, IDPH must also notify any interested parties when an exemption request has been made and issued.

In addition, IDPH must annually (1) notify health care providers about the law's requirements and post the notification on its website, (2) encourage health care providers to increase flu immunization rates for people recommended to receive it, and (3) report to the legislature on its efforts to inform health care providers about thimerosal-free vaccines (410 Illinois Compiled Statutes 51/1).

Missouri

Since April 1, 2007, Missouri law has prohibited the administration of any vaccine containing more than a trace amount of mercury (one microgram per 5/10 milliliter dose) to a knowingly pregnant woman or child under age three. It requires health insurers operating in the state to reimburse enrollees for mercury-free vaccine at the same percentage rate as those containing mercury or any other preservative. The law allows the Department of Health and Senior Services director to administer mercury-containing vaccines to these groups if the director and governor determine there is an actual or potential public health emergency resulting in a mercury-free vaccine shortage (Missouri Revised Statutes, Title 12 § 191.235).

New York

New York law prohibits the administration of vaccines containing more than trace amounts of thimerosal to a (knowingly) pregnant woman or a child under age three, with certain exceptions. Trace amounts are defined as follows:

1. flu vaccines containing no more than 1.25 micrograms of mercury per 0.5 milliliter dose for pregnant women and 0.625 micrograms of mercury per 0.25 milliliter dose for children under age three, and

2. all other vaccines containing no more than 0.5 micrograms of mercury per 0.5 milliliter dose.

If vaccine that meets these standards is unavailable, the state health commissioner may authorize the use of other vaccines. The commissioner must annually determine that there is an adequate supply of flu vaccine that complies with the law. Before a vaccine that contains more than trace amounts of thimerosal is administered, the pregnant woman and the child's parent must give written informed consent.

The law also allows the commissioner to authorize the use of vaccines containing more than trace amounts of thimerosal when it is necessary to prevent or respond to an outbreak of disease and there are insufficient amounts of vaccine containing trace amounts of thimerosal. During an outbreak informed consent is not required. The law took effect July 1, 2008 (New York Consolidated Laws, Public Health, Article 21, Title 1, § 2112).

Washington

Since July 1, 2007, Washington law has prohibited the administration of vaccines that contain more than trace amounts of mercury to (knowingly) pregnant women and children under age three. A trace amount is defined as less than 0.5 micrograms per 0.5 milliliter dose except for flu vaccines, which may contain up to 1.0 micrograms per 05. milliliter dose.

The law allows the health department secretary to administer mercury-containing vaccines or injections to these groups if the secretary or a local public health officer determines that there is (1) an outbreak of vaccine-preventable disease or (2) a thimerosal-free vaccine shortage. If thimerosal-containing vaccines are administered, the pregnant woman and the child's parent or legal guardian must be informed that the vaccine or injection contains mercury (Revised Code of Washington, 70.95M.115).

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