What side effect does the H1N1 vaccine have on an unborn child?

Answer 1

The Food and Drug Administration (FDA) approved the inactivated ("dead") virus vaccines for pregnant women. The nasal mists containing live weakened virus is not approved for pregnant women. The risk to the unborn fetus was considered in the trials and approval process. The guidance from the CDC is very clear that the risk of not getting vaccinated against A-H1N1/09 to pregnant women and their unborn fetus is much greater than the risk of using the vaccines. Obstetricians are recommending H1N1/09 vaccinations to their patients. The vaccine is made exactly like the seasonal flu shots have been made for decades with a proven safety record, so there is no reason to think the same vaccine made with inert particles from a different virus strain would prove any less safe.

The following are excerpts from a September 3, 2009guidance document from the US Centers for Disease Control and Prevention (CDC), 2009 H1N1 Influenza Vaccine and Pregnant Women:

Influenza vaccines have not been shown to cause harm to a pregnant woman or her baby. The seasonal flu shot (injection) is proven as safe and already recommended for pregnant women. The 2009 H1N1 influenza vaccine will be made using the same processes and facilities that are used to make seasonal influenza vaccines.

It is important for a pregnant woman to receive the 2009 H1N1 influenza vaccine as well as a seasonal influenza vaccine. A pregnant woman who gets any type of flu is at risk for serious complications and hospitalization. Pregnant women who are otherwise healthy have been severely impacted by the 2009 H1N1 influenza virus (formerly called "novel H1N1 flu" or "Swine Flu"). In comparison to the general population, a greater proportion of pregnant women infected with the 2009 H1N1 influenza virus have been hospitalized. In addition, severe illness and death has occurred in pregnant women. Six percent of confirmed fatal 2009 H1N1 flu cases thus far have been in pregnant women while only about 1% of the general population is pregnant. While hand washing, staying away from ill people, and other steps can help to protect pregnant women from influenza, vaccination is the single best way to protect against the flu.

There are two types of flu vaccine. Pregnant women should get the "flu shot"- an inactivated vaccine (containing fragments of killed influenza virus) that is given with a needle, usually in the arm. The flu shot is approved for use in pregnant women. The other type of flu vaccine - nasal-spray flu vaccine (sometimes called LAIV for "live attenuated influenza vaccine)-is not currently approved for use in pregnant women. This vaccine is made with live, weakened flu viruses that do not cause the flu). LAIV (FluMist®) is approved for use in healthy* people 2-49 years of age who are not pregnant. In addition to protecting her from infection, infants less than 6 months old will not be able to be vaccinated so it is recommended that everyone who lives with or provides care for infants less than 6 months of age receive both the seasonal influenza vaccine and 2009 H1N1 influenza monovalent vaccine to provide protection for the infant.

One recent study conducted in Bangladesh, assessed the effectiveness of influenza immunization for mothers and their young infants. Inactivated influenza vaccine reduced proven influenza illness by 63% in infants up to 6 months of age. This study confirmed that maternal influenza immunization is a strategy with substantial benefits for both mothers and infants. There is no evidence that thimerosal (used as a preservative in vaccine packaged in multi-dose vials) is harmful to a pregnant woman or a fetus. However, because some women are concerned about exposure to preservatives during pregnancy, manufacturers will produce preservative-free seasonal and 2009 H1N1 influenza vaccines in single dose syringes for pregnant women and small children. CDC recommends that pregnant women may receive influenza vaccine with or without thimerosal. People for whom the 2009 H1N1 influenza vaccine is recommended should receive it, even if they have had an influenza-like illness previously, unless they can be certain they had 2009 H1N1 influenza based on a laboratory test that can specifically detect 2009 H1N1 viruses. CDC recommends that persons who were tested for 2009 H1N1 influenza discuss this issue with a healthcare provider to see if the test they had was either an RT-PCR or a viral culture that showed 2009 H1N1 influenza. There is no harm in being vaccinated if you had 2009 H1N1 influenza in the past.

Pregnant women are encouraged to get vaccinated against the flu. As always, when pregnant, check with your obstetrician before taking any medication.

You should not get the vaccine if you are allergic to eggs** or sulfa drugs. Inform your health care professional if you have ever had a severe (life-threatening) allergy to eggs or to any other substance in a vaccine (some vaccines contain traces of neoporin, gentamicin and polymixin).

**New studies show that an allergy to eggs, or other chicken proteins, may not prohibit some people from getting a flu vaccination. See the related questions for more information.

See the related links section below for a link to the full CDC guidance document.