WSR 11-14-043


[ Filed June 28, 2011, 11:35 a.m. ]

Suspension of Legal Limits of Mercury-Containing Vaccine for 2011 Seasonal Influenza


June 2011

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 eighteen years of age receiving the vaccine.

Why is the law being suspended? Effective June 27, 2011, the secretary of health extended the suspension of 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 2011-2012 single dose thimerosal-free flu vaccine that comes in prefilled syringes may contain trace amounts of natural rubber latex.

This means the health care provider may advise that children under three and pregnant women who have or may have latex allergies avoid vaccine from thimerosal-free single dose syringes. Supplies of other types of thimerosal-free flu vaccine are limited and can't be used for everyone.

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 used in some vaccines - is an organic compound that contains a form of mercury called ethylmercury. This is different from the type found in the environment called methylmercury. Studies comparing ethylmercury and methylmercury suggest that the type used in the flu vaccine is removed from the body more quickly than 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. There's no reliable evidence that the small doses of thimerosal in flu vaccine causes harm, except for minor swelling and redness at the injection site. A wide safety margin was included in the allowable levels for organic mercury exposure. The benefits of thimerosal-containing influenza vaccine outweigh any theoretical risk.

Where can I get more information? Flu vaccine information ( is available on-line


1National Network of Immunization Information:

Food and Drug Administration at

Washington State Code Reviser's Office