Seasonal Influenza FAQs for Patients
1. I am pregnant. Is it safe to receive the influenza immunization (flu shot)?
Flu shots are a safe way to protect the mother and her unborn child from serious illness and complications of flu. The flu shot has been given to millions of pregnant women over many years, and flu shots have not been shown to cause harm to pregnant women or their babies. It is very important for pregnant women to get the flu shot. The flu shot given during pregnancy has been shown to protect both the mother and possibly her baby (up to 6 months old) from flu. This is especially important for infants younger than 6 months, since they are too young to be vaccinated and have no other way of receiving vaccine antibodies.
2. During which trimester is it safe to have an influenza vaccine?
The seasonal influenza (flu) vaccines are recommended for pregnant women at any time during pregnancy and can be given during any trimester. Pregnant women are advised to get vaccinated as quickly as they can and speak to their midwife or doctor about being immunized.
3. What type of seasonal flu vaccine should pregnant women receive for the 2011-2012 flu season?
There are two types of influenza vaccines. One is the inactivated influenza vaccine (“flu-shot”) that is given with a needle, usually in the arm. This is the type of vaccine that the Advisory Committee on Immunization Practices (ACIP) and the American College of Obstetricians and Gynecologists recommends that pregnant women should receive.
The other type of influenza vaccine, the “nasal-spray” influenza vaccine (sometimes called LAIV for “live attenuated influenza vaccine”) is made with live, weakened influenza virus. The live attenuated (weakened) influenza vaccine is contraindicated by the ACIP and the College for use in pregnancy.
4. Are there flu vaccines that pregnant women should not get?
The seasonal 2011 –2012 flu vaccines can be given by shot or by nasal spray. Pregnant women should get the “flu shot”—a vaccine made with killed flu virus. This one is given with a needle, usually in the arm. The other type of flu vaccine—a nasal spray—is NOT approved for pregnant women. This vaccine is made with live, weakened flu virus. The nasal spray vaccine is safe for women after they have delivered, even if they are nursing.
5. I am breastfeeding my baby. Is it safe to get vaccinated?
Yes. Influenza vaccines can be given to breastfeeding mothers if they were not immunized when they were pregnant. Breastfeeding women can receive either the shot or the nasal spray form of the vaccine. Breastfeeding is fully compatible with flu vaccination, and preventing the flu in mothers can reduce the chance that the infant will get the flu. Also, by breastfeeding, mothers can pass on to the infant the antibodies that their bodies make in response to the flu shot, which can reduce the infant’s chances of getting sick with the flu. This is especially important for infants younger than 6 months, since they are too young to be vaccinated and have no other way of receiving vaccine antibodies. In addition:
The influenza virus is not transmitted by breastmilk.
Mothers who believe they may be infected should be sure to wash their hands before breastfeeding.
Be sure to use clean burp cloths, and consider wearing a face mask.
Parents and caregivers of infants younger than 6 months should receive the flu shot to prevent illness.
6. I am pregnant. Are preservatives in influenza vaccines safe for my baby?
The type of mercury (thimerosal) used as a preservative in some vaccines has not been shown to be harmful to a pregnant woman or her unborn baby. However, because some women are concerned about exposure to preservatives during pregnancy, manufacturers will produce preservative-free seasonal and H1N1 influenza vaccines in single-dose syringes for pregnant women and small children. The CDC recommends that pregnant women may receive influenza vaccine with or without thimerosal.
7. What can I do to protect myself, my baby, and my family against the flu?
Getting a flu shot is the first and most important step in protecting against the flu. The flu shot given during pregnancy has been shown to protect both the mother and possibly her baby (up to 6 months old) from flu. Babies younger than 6 months cannot get the flu shot. In addition, take these everyday steps to protect the health of you and your family:
Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
Wash your hands often with soap and water, especially after you cough or sneeze. You can also use an alcohol-based hand cleaner.
Avoid touching your eyes, nose, or mouth. Germs spread this way.
Try to avoid close contact with sick people.
While sick, limit contact with others as much as possible to keep from infecting them.
8. I am now pregnant. Do I need to be immunized for H1N1 in the 2011-2012 flu season if I received the H1N1 immunization during the 2009-10 flu season?
Yes. People who received the 2009 H1N1 (pandemic) influenza vaccine, or had pandemic flu in 2009, should still get the 2011–2012 seasonal influenza vaccine.
Please see our Resource area for a listing of Patient Education Materials.
For more information, visit CDC's section on Seasonal Flu Vaccine Safety and Pregnant Women.
Seasonal Influenza FAQs for Ob-Gyns
1. Should pregnant women be immunized against seasonal influenza (flu)?
Yes. Influenza vaccination is an essential element of prenatal care because pregnant women are at increased risk for serious illness and mortality due to influenza. In addition, maternal immunity is the only effective strategy in newborns because the vaccine is not approved for use in infants younger than 6 months.
2. Is it safe for pregnant women to be immunized against seasonal influenza?
No study to date has shown an adverse consequence of inactivated influenza vaccine in pregnant women or their offspring. The influenza vaccine is made the same way each year, with the only difference being the use of a new strain of influenza. There have been no reports of any adverse outcomes in pregnant women or their infants.
3. During which trimester should pregnant women be immunized?
All women who will be pregnant during influenza season (October through May) should receive inactivated influenza vaccine at any point in gestation. Live attenuated influenza vaccine is contraindicated for pregnant women.
4. Is it safe for pregnant women to receive an influenza vaccine that contains mercury (thimerosal)?
Yes. Thimerosal, a mercury-containing preservative used in multidose vials, has not been shown to cause any adverse effects except for occasional local skin reactions. There is no scientific evidence that thimerosal-containing vaccines cause adverse effects in children born to women who received vaccines with thimerosal.
A study of influenza vaccination examining over 2,000 pregnant women demonstrated no adverse fetal effects associated with the influenza vaccine. Case reports and limited studies indicate that pregnancy can increase the risk for serious medical complications of influenza. One study found that during an average flu season, 25 of every 10,000 women in their third trimester of pregnancy will be hospitalized for flu-related complications.
Additionally, excess influenza-associated deaths among pregnant women have been documented during influenza pandemics. Because pregnant women are at increased risk for influenza-related complications and because a substantial safety margin has been incorporated into the health guidance values for organic mercury exposure, the benefits of influenza vaccine with reduced or standard thimerosal content outweigh the theoretical risk, if any, of thimerosal.
For more information visit CDC's section concerning Seasonal Flu Vaccine Safety and Pregnant Women