WSR 10-21-018


[ Filed October 7, 2010, 4:15 p.m. ]

Suspension of Legal Limits of Mercury-Containing Vaccine for 2010 Seasonal Influenza


October 2010

Why am I receiving this notice? Washington law sets a limit on how much mercury can be in vaccines for pregnant women and children younger than three years old. The law allows the secretary of health to suspend the state's legal mercury limit for a vaccine if there's a shortage of vaccine available to protect the public's health against vaccine-preventable disease.

When the limits are suspended, state law requires the following people be informed they are being given a vaccine containing mercury levels over those limits:

Women known to be pregnant or lactating.
The parent or legal guardian of a child under 18 years of age receiving the vaccine.

Why is the law being suspended? Effective October 7, 2010, the secretary of health suspended the state's legal limits on mercury in flu vaccine for people in these groups who have or may have latex allergies. The tip cap of the 2010-2011 single dose thimerosal-free flu vaccine that comes in pre-filled syringes may contain trace amounts of natural rubber latex.

This means that children under three and pregnant women who have or may have latex allergies may be advised by their health care provider to not get the thimerosal-free single dose syringes. Supplies of other types of thimerosal-free flu vaccine are limited and can't be used for all people.

Suspending the thimerosal limits law removes barriers so people can choose to be protected. Pregnant women, children under three, and people allergic to latex, including those with spina bifida who are considered at high risk for a latex allergy, are at high risk for serious complications if they get the flu. Vaccination is voluntary, and we encourage people to talk to their health care provider about getting vaccinated.

What is mercury and what is thimerosal?1 Thimerosal - a preservative still used in some vaccines - is a mercury-containing organic compound that has a form of mercury called ethylmercury, which is different than the form in the environment called methylmercury. Studies comparing ethylmercury and methylmercury suggest that they are processed differently in the human body. Ethylmercury is broken down and excreted much more rapidly than methylmercury. It appears that ethylmercury (the type of mercury in the influenza vaccine) is removed from the body more quickly than methylmercury (the type of mercury in the environment). The federal Food and Drug Administration (FDA) licenses flu vaccines and does not place any limits on thimerosal in vaccines for any people.

1 Children's Hospital of Philadelphia at Food and Drug Administration at

Where can I get more information? For more information about flu vaccine, visit:

Washington State Code Reviser's Office