October 22nd, 2009
01:13 PM ET

Do the flu vaccines contain thimerosal?

By Ann J. Curley
CNN Medical Assignment Manager

Many of our readers are still asking questions about H1N1 and seasonal influenza. Today we’ve got a question from Patty:

I am a 63-year-old health care worker in relatively good health, and I’m caring for a 2-month-old infant (my granddaughter). I have had a reaction to thimerosal in the past. It was used as a preservative in contact lens solution.

Is thimerosal used as a preservative in either seasonal flu vaccine or H1N1 vaccine? Are there available alternatives to these vaccines? How would I access them?

Patty Holly


Thank you for your question. It’s important that you make your health care provider aware of your sensitivity to thimerosal, which is a preservative used in many products, including some vaccines, nasal products, and eye solutions.

According to the Centers for Disease Control and Prevention, the 2009 H1N1 influenza vaccines approved by the FDA are being manufactured with and without thimerosal.

Multi-dose vials of flu vaccine need to contain a preservative to prevent bacterial contamination, which can occur when multiple syringes are inserted into the same bottle.  However, some manufacturers also produce single-dose flu shots, which do not require any preservatives.

The nasal flu vaccine – both for seasonal flu and H1N1 – is always thimerosal-free. However, it is recommended only for people ages 2 to 49 who have no underlying health problems. The nasal spray vaccine is made from a weakened live virus and is not recommended for people with autoimmune disorders, pregnant women, and patients with certain chronic health problems, including diabetes, heart disease, asthma, and lung disease. Unfortunately, you can’t take the nasal flu vaccine because you are 63. You can find more information about the live vaccine here.

Ask your doctor for a thimerosal-free flu shot. If he or she doesn’t have one, you can visit the CDC’s H1N1 Web site and check out its “flu shot locator” .  It has links to the Web site of each state’s health department, with specific information about where vaccine can be found.

The Centers for Disease Control and Prevention has a lot of useful information about both seasonal flu and H1N1 flu on its Web site. Also be sure to check out CNN.com’s flu page.

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soundoff (3 Responses)
  1. Rosemerry Cleveland

    I am trying to find out if the swine flu injection vaccination contains squalene. I have yet to find a list of the actual ingredients.

    October 23, 2009 at 11:42 | Report abuse | Reply
  2. Martina

    Thank you for the question on thimerosal. I too was wondering about the single dose injection for my son as he is too young for the mist, and also has reactive airway disease. I think that our health care providers should give us the option of choosing thimerosol-free vaccines being that you don't know if you are going to have a reaction until it is in your system. I've heard that these reactions can span from a mild allergy to a neurologic crisis. When it comes to our children, we want to do the right thing and immunize, but we do not want to take a chance on mercury-based preservatives being injected into their little bodies.

    October 30, 2009 at 14:49 | Report abuse | Reply
  3. Dong Grullon

    I like this post, enjoyed this one thanks for posting.


    November 25, 2020 at 11:58 | Report abuse | Reply

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Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.