H1N1 Flu Vaccine Questions and Concerns Continue on Thimerosal and Pregnancy

By Barbara Ficarra, RN, BSN, MPA

Information on the H1N1 swine flu vaccine continues to mount, and questions linger.

In a recent post, H1N1 Swine Flu Vaccine Fears Addressed – Single vs. Multi-Dose, Adjuvants, Thimerosal and More, Bruce B. Dan, MD, a specialist in infectious diseases, answered a series of questions related to the H1N1 flu vaccine.

Our readers have a couple additional questions and our expert, Dr. Bruce B. Dan answers them to help alleviate your fears.

Our Reader, Arly Helm writes:

“To avoid confusion and controversy, thimerosal was removed from childhood vaccines.” But not removed from the child dose of H1N1, is that correct?”

Our Expert, Bruce B. Dan, MD replies:

“All single-dose syringes of H1N1 influenza vaccine including those for children and pregnant women are thimerosal-free, which addresses any concerns people may have about this preservative (inhaler spray vaccine products are also thimerosal-free).  The only H1N1 vaccines that contain thimerosal are those that are produced in multi-dose vials (thimerosal is added to the vials to make them safer by preventing bacterial contamination when the vial is punctured multiple times giving the vaccine to multiple people).  The pediatric scientific and medical community has looked carefully at thimerosal and determined that there is no evidence that it causes any harm.”

Our Reader, Rosalind Smith writes:

I want to know if the H1N1 shot is safe for women who are in their second trimester of pregnancy?  I was told to get the shot and did but now I’m really scared and worried that I may have made a mistake. Can you please get back to me and let me know if I did the right thing.

Our Expert, Bruce B. Dan, MD replies:

“You’ve actually done the best thing possible for yourself and your unborn child.   The H1N1 vaccine is safe when given at anytime during pregnancy.  More importantly when you’re pregnant you are at greater risk for serious illness if you contract H1N1 influenza, more likely to be admitted to a hospital, and more likely to die from the infection.  When you get a flu shot it not only protects you from influenza but your baby as well.  The antibodies your immune system produces in response to the flu shot cross the placenta and protect your baby after birth for several months, which is especially important since infants under 6 months of age who are not eligible to get the flu vaccine.  Also good news is that breastfeeding passes antibodies to your newborn reducing the baby’s chance of getting the flu.  It’s important to remember that the “flu shot” you got, a vaccine made with killed flu virus, is the one pregnant women should receive.  The other flu vaccine, which is made with a live, weakened flu virus and given by nasal spray, is not approved for pregnant women.”

Please let us know if you have any further questions or concerns.  Here are some additional posts that may be helpful.



Swine Flu: H1N1 Flu Vaccine – Who Should Get It, Who Shouldn’t Get It and Is It Safe?
Medical Experts Respond to Swine Flu: H1N1 Flu Vaccine – Who Should Get It, Who Shouldn’t Get It and Is It Safe?

H1N1 Swine Flu Vaccine Fears Addressed – Single vs. Multi-Dose, Adjuvants, Thimerosal and More

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    I would be a bit concerned about getting the swine flu virus if I were a pregnant mother. However, I would be even more concerned if I had a newborn that had not been vaccinated against the H1N1 strain, so I believe the risk of getting the vaccine, if there is any, is worth it. 

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