Vaccines During Pregnancy and Breastfeeding

pregnant bellyCongratulations on your pregnancy! You're eating right, getting extra rest and taking your prenatal vitamins. After all, you want to do everything you can to ensure a healthy baby! But have you given any thought to protecting yourself and your baby against infection?

It's important. That's why the U.S. Centers for Disease Control and Prevention's (CDC) Advisory Committee on Immunization Practices (ACIP) has specific recommendations for pregnant and breastfeeding women (see chart below). The committee notes that there is no evidence of risk to your developing baby if you are vaccinated with an inactivated viral or bacterial vaccine while pregnant. In either case, the committee notes, the "benefits of vaccinating pregnant women usually outweigh the potential risks when the likelihood of disease exposure is high, when infection would pose a risk to the mother or fetus, and when the vaccine is unlikely to cause harm."

The chart provides the committee's recommendations for vaccines during pregnancy. In this article, however, we focus on one specific vaccine: the flu vaccine. For while the ACIP lists five vaccines that can be given during pregnancy, only one is "recommended": the influenza vaccine. The other four—hepatitis B, tetanus-diphtheria, meningococcal and rabies—are options if you have been or could be exposed to the disease.

So what makes the flu vaccine so special? Well, you're much more likely to be exposed to influenza in any given year than meningitis or rabies—other viral illnesses for which vaccines exist. Plus, pregnancy-related changes in your immune and respiratory systems increase your vulnerability to the flu virus. And if you do get the flu while you're pregnant, you're more likely to be hospitalized with complications. Another good reason to get vaccinated against the flu is that a recent study found that your vaccine could protect your baby during his or her first five months—when infants can't receive a flu vaccine, yet when they are very vulnerable to flu-related complications.

Plus, unlike many vaccines, we have some fairly good evidence that the inactive, injectable form of the vaccine is very safe for pregnant women and their fetuses.

But you're not the only one who needs a vaccine. The people around you should also get a flu vaccine this season. That reduces the risk that they'll catch the flu and bring it home to you or your newborn. So let's sort out the what, why and when of flu vaccines.

What. There are two main types of flu vaccine: The inactivated virus vaccine, delivered as an injection; and the attenuated virus vaccine, delivered as a nasal spray. Pregnant women should only receive the inactivated, injection form. The nasal spray vaccine is approved only for use in healthy people 2 to 49 years of age who are not pregnant.

One other thing: If you've had a severe reaction to a flu vaccine in the past, you should not be immunized, whether or not you're pregnant or breastfeeding. Also, if you have a fever, wait until you're better before getting the vaccine. If you are allergic to eggs, talk to your health care provider before getting vaccinated. You may be able to receive an egg-free version of the vaccination.

You have another consideration when it comes to the vaccine: thimerosal or thimerosal free? Thimerosal is a mercury compound that has been used for more than 80 years to preserve vaccines. Numerous studies find no harmful effects from the preservative in children or adults. Still, some people worry about it, which is why manufacturers have now made a thimerosal-free vaccine available.

Here's something else you should be aware of: The vaccine is not foolproof. It will not provide 100 percent protection against the flu. When the vaccine and the circulating viruses are similar, the vaccine can prevent the flu among 70 to 90 percent of healthy adults under 65.

Even if you do get the flu, the vaccine can still protect you against flu-related complications by minimizing the severity of the illness.

And, contrary to flu myths out there, you cannot get the flu from a flu shot or the nasal vaccine. If you get sick after a vaccine, it's just coincidence. In fact, the most common side effect of the shot is a little soreness at the injection site, and the most common side effect of the spray is a runny nose or nasal congestion.

When. The best time for a flu shot is between September and December, before flu season really peaks in January, February or later. But if the New Year rolls around and you realize you never got vaccinated, relax, it's not too late to get your flu shot. It usually only takes about two weeks for your body to make antibodies (immune system proteins that help your system recognize the flu virus) to the virus. So no matter when you get vaccinated, you still get some protection.

While a single vaccine lasts the entire season, it won't protect you next year because your immunity fades. Plus, flu viruses change from year to year. That's why it's important to get vaccinated every year.

Who. While anyone six months and older should get vaccinated (unless they meet the criteria noted earlier), the CDC particularly recommends flu vaccines for people 65 or older; those living in a nursing home or other medical care facility; those with respiratory diseases, anemia or other chronic lung, heart, kidney or blood disorders, including diabetes; those with a weakened immune system, either from medication, cancer treatment or disease such as HIV/AIDS; and those with dementia, spinal cord injury, seizure disorder or other neuromuscular problem that could affect breathing; infants and children from 6 months to 5 years old, especially any child with chronic health conditions or who is taking aspirin as a long-term therapy; and women who are pregnant during flu season. These individuals have a much higher risk of complications.

One more thing: If flu season rolls around while you're breastfeeding your new baby, you should still get vaccinated. This time, however, you're eligible for the nasal, or "attenuated," version of the vaccine. In fact, you can have any type of vaccine—except the smallpox vaccine—while breastfeeding with no worries about it negatively affecting your baby in any way.

So what are you waiting for? Pick up the phone and make an appointment for a flu vaccine. You have too much to do to wind up sick this winter!

Vaccinations for Pregnant Women

Vaccine
Should be considered if otherwise indicated
Not advisable during pregnancy
Special/conditional recommendation
  Hepatitis A     Safety during pregnancy has not been determined, but the theoretical risk to the fetus is expected to be low.
Hepatitis B
X
   
Human Papillomavirus (HPV)     Quadrivalent HPV vaccine not recommended during pregnancy.
Influenza (Inactivated) Recommended (routine)    
Influenza (Live attenuated virus)  
X
 
Measles  
X
 
Meningococcal (MCV4)     No data available on safety during pregnancy.
Mumps  
X
 
Pneumococcal     Safety during the first trimester of pregnancy has not been evaluated, although no adverse consequences have been reported among newborns whose mothers were inadvertently vaccinated during pregnancy.
Polio (IPV)     No adverse effects have been documented among pregnant women or their fetuses, but vaccination of pregnant women should be avoided on theoretical grounds. If a pregnant woman is at increased risk for infection and requires immediate protection against polio, IPV can be administered in accordance with the recommended schedules for adults.
Rubella  
X
 
Tetanus—Diphtheria
X
  Previously vaccinated pregnant women who have not received a Td vaccination within the 10 years should receive a booster dose.

Pregnant women who have not received three doses of a vaccine containing tetanus and diphtheria toxoids should complete a series of three vaccinations, with two doses administered during pregnancy to ensure protection against maternal and neonatal tetanus.

Ideally, wait until the second trimester of pregnancy to administer.

 

Tetanus— Diphtheria—Pertussis (Tdap)     Pregnancy is not a contraindication for use of Tdap, but very little data on its use is available.
Varicella  
X
 
Travel & Other Anthrax     Vaccinate only if the potential benefits of vaccination outweigh potential risks to the fetus.
BCG  
X
 
Japanese Encephalitis     No specific information is available on the safety during pregnancy. Vaccination poses an unknown but theoretical risk to the fetus, and the vaccine should not be routinely administered during pregnancy.
Meningococcal (MPSV4)
X
   
Rabies
X
   
Typhoid     No data have been reported on the use of any of the three typhoid vaccines among pregnant women.
Smallpox  
X
Pregnant women who have had a definite exposure to smallpox virus (i.e., face-to-face, household or close-proximity contact with a smallpox patient) and are at high risk for contracting the disease should be vaccinated.
Yellow Fever     Safety during pregnancy has not been established, and the vaccine should be administered only if travel to an endemic area is unavoidable and an increased risk for exposure exists.
Zoster  
X
 

Source: U.S. Centers for Disease Control and Prevention, May 2007.