New Recommendation on RSV Immunization in Pregnancy

The CDC has recently released new guidelines to help protect infants against RSV this winter, including encouraging the RSV vaccine during pregnancy.

Andaluz midwives support informed choice and medical freedom, and are also committed to presenting new guidelines as they emerge so you can make the choice that is right for you.

What is RSV?

RSV is short for respiratory syncytial virus.


For adults and older children, this virus usually presents as a cold with mild symptoms like runny nose, sore throat, and cough.

Immunity to RSV grows with exposure, so new babies have not yet had a chance to build natural immunity. Without this immunity, they can develop more severe respiratory symptoms that can lead to pneumonia and bronchitis that may require hospitalization.

In fact, RSV is the most common cause of hospitalization in infants in the US.

What is the new recommendation?

The new CDC recommendation is that pregnant people receive an RSV vaccine between week 32-36 of pregnancy.

It is most important to receive the vaccine during the months of September through January, since RSV is a seasonal virus.

Why is the recommendation being made?

There is an infant version of the RSV vaccine, but due to high demand there is a supply shortage.

With the infant version of the vaccine potentially unavailable, pregnant people can receive the adult version of the vaccine themselves, and pass immunity on to their babies before birth.

According to the American Academy of Pediatrics, when the RSV vaccine is given at 32-36 weeks’ gestation, clinical trials have shown that at 90 days post-vaccination it “reduced the risk of severe disease by 91% compared to placebo.”

The vaccine when given prenatally continues to provide protection for infants for many months, with clinical trials showing that “it reduced the risk of medically attended lower respiratory tract disease by 57% and severe disease by 77% in infants six months after birth.”

Babies should not need to receive the RSV vaccine if it was given to their parent during the 32-36 week window, unless babies are born less than 14 days after the vaccination is given.

Safety and Decision Making

The primary concern for giving the vaccine during pregnancy is an increased risk in preterm birth. Clinical trials found that there was a preterm birth rate of 5.7% for those who were vaccinated between 24-36 weeks gestation, comparted to a premature birth rate of 4.7% in the placebo group (a 1% increase).

This is one reason why the timing of the vaccine is important. When given between 32-36 weeks gestation, the preterm birth rates were 4.2% for the vaccinated group and 3.7% for the placebo group (a 0.5% increase). The study also found that most preterm births occurred 30 days after the vaccine was given.

As always, your Andaluz midwife is available to discuss the risks and benefits of receiving the RSV vaccine during pregnancy with you if you have questions, and will respect your individual choices.


We do not offer vaccines at the birth center. If you are interested in receiving the RSV vaccine, you should see your primary care provider.

You can also check out our blog post from last winter with tips to help keep your baby safe from RSV.