RSV (respiratory syncytial virus) is the most common cause of serious respiratory infection in infants. Every year the virus leads to thousands of hospitalizations among children under one year of age, with the very youngest being most at risk.

There is now a vaccine that can protect your baby from birth. Abrysvo from Pfizer is approved for use in pregnant women and provides newborns with important antibodies against RSV through the placenta.

Here you'll find everything you need to know about the RSV vaccine for pregnant women, from who should get it, to cost, side effects, and what the CDC and AAP recommend.

What Is RSV and Why Is It Dangerous for Babies?

RSV (respiratory syncytial virus) is a highly contagious respiratory virus that affects people of all ages. In older children and adults, it usually only causes cold symptoms. But for infants, particularly those under three months, the virus can lead to serious illness.

When RSV attacks the lower airways of young children, it can develop into bronchiolitis, inflammation of the small branches of the airways (bronchioles). Symptoms include rapid and labored breathing, coughing, reduced appetite, and general fatigue.

Who Is Most at Risk?

Some groups have a higher risk of serious RSV disease:

Premature babies (born before week 37)
Infants under 3 months, the most vulnerable
Children with congenital heart disease or lung disease
Children with weakened immune systems

Around 1–3 percent of infants who are infected need hospitalization, according to the CDC. For the very youngest, RSV can in rare cases cause breathing pauses and require intensive care.

RSV Season

RSV follows a seasonal pattern. Outbreaks typically start in the fall and continue through winter, with a peak usually in December–January. After the pandemic, the seasonal pattern has been somewhat unpredictable, with severe outbreaks outside the usual season.

In most of the continental US, the CDC recommends the maternal RSV vaccine from September through January, so that babies are born with protection for their first RSV season. If you are 32 to 36 weeks pregnant outside those months, your baby can get an RSV antibody shot instead.

RSV Vaccine for Pregnant Women. Abrysvo

Abrysvo is a vaccine developed by Pfizer that was approved in the US and EU in 2023. It is approved for two indications:

Pregnant women (gestational weeks 32–36), to protect infants against RSV-related lower respiratory tract disease through passive transfer of antibodies
Adults 60 years and older, for personal protection against RSV

The vaccine does not contain live virus and therefore cannot give you or the baby an RSV infection. It works by stimulating your body to produce antibodies against RSV. These antibodies are transferred to the baby via the placenta and provide protection during the first months of life.

How Effective Is the Vaccine?

Studies show that Abrysvo reduces the risk of RSV-related hospitalizations in infants by approximately 68 percent in the first 90 days after birth. After 180 days (six months), the effect is still significant, with a reduction of around 57 percent.

The vaccine protects against both subtypes of RSV (RSV-A and RSV-B).

Think of it this way: the vaccine acts as a temporary "borrowed protection" for the baby. The antibodies you transfer through the placenta give the child a head start in facing RSV during the first critical months of life.

Who Should Get the RSV Vaccine?

The CDC recommends that every baby be protected against severe RSV in one of two ways: the maternal RSV vaccine during pregnancy, or an RSV antibody shot given to the baby. Most babies do not need both. The maternal vaccine is recommended if you:

Are between 32 and 36 weeks pregnant
Reach that window between September and January (in most of the US)
Have not had an RSV vaccine in an earlier pregnancy. If you have, the CDC does not currently recommend a second dose, and your baby should get the antibody shot after birth instead.

Talk with your OB, midwife, or doctor to assess whether the vaccine is right for your situation. They can help you weigh the benefits against any risks based on your individual health circumstances.

Who Should Not Get the Vaccine?

You should not get Abrysvo if you:

Have had a severe allergic reaction (anaphylaxis) to a previous dose of the vaccine or any of its ingredients
Are seriously ill with a high fever (vaccination should then be postponed)

Pregnant women who are unsure should consult their doctor.

When During Pregnancy Should the Vaccine Be Given?

Abrysvo is approved for use between gestational weeks 32 and 36. The CDC and AAP recommend vaccination during this window so your body has time to produce antibodies and transfer them to the baby via the placenta.

The vaccine is also seasonal. In most of the continental US, it is given from September through January. Timing can differ in Alaska and in tropical areas such as Hawaii, Puerto Rico, and southern Florida, where RSV season is less predictable.

For the baby to get optimal protection, there should be at least two weeks between vaccination and birth. If the vaccine is given very late in pregnancy, there may not be enough time for sufficient antibodies to be transferred.

The CDC says the vaccine should not be given after 36 weeks and 6 days of pregnancy. By then there is unlikely to be enough time for the antibodies to reach the baby, so the CDC recommends an RSV antibody shot for the baby instead.

Can I Get the RSV Vaccine and the Tdap Vaccine at the Same Time?

Yes. According to the CDC, the maternal RSV vaccine can be given at the same visit as the Tdap vaccine. It can also be given at the same visit as flu and COVID-19 vaccines.

The FDA label adds two details. When Abrysvo and Tdap were given together to women who were not pregnant, antibody levels against whooping cough were lower than when Tdap was given alone, and the label says the clinical relevance of this finding is unknown. Giving the two together has not been studied during pregnancy.

Planning tip: Tdap is recommended in weeks 27 to 36 of pregnancy, and the RSV vaccine in weeks 32 to 36 from September through January. If your timing overlaps, you can ask for both at the same visit. Check your insurance coverage for the RSV vaccine before your appointment.

Follow your prenatal appointments and use our due date calculator to keep track of which week you are in.

Side Effects and Safety

Abrysvo has undergone extensive clinical studies with thousands of pregnant participants. Its safety profile is considered good by both the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA).

Common Side Effects

Most side effects are mild and temporary:

Pain at the injection site, the most common side effect
Redness and swelling at the injection site
Headache
Muscle aches
Fatigue

Side effects typically resolve within a few days.

What About the Risk of Preterm Birth?

In the main clinical trial, preterm births were more common in the vaccine group than in the placebo group (5.7 percent vs. 4.7 percent). Among participants vaccinated at 32 to 36 weeks, the window used today, the figures were 4.3 percent vs. 3.7 percent. According to the FDA label, the available data are insufficient to establish or exclude a causal relationship.

The FDA label limits use to 32 through 36 weeks of pregnancy to avoid the potential risk of preterm birth with use before 32 weeks.

What About Blood Pressure During Pregnancy?

The CDC lists hypertensive disorders of pregnancy, including preeclampsia, as a possible risk that is still under study. Ask your provider if you have questions about what this means for you.

No negative effects on infants up to 24 months of age have been found in follow-up studies. The vaccine has been assessed as safe for both mother and child by the FDA and EMA.

Is the Vaccine Covered by Insurance?

The RSV vaccine (Abrysvo) is FDA-approved and available in the United States. Coverage varies by insurance plan, many plans cover it as a preventive care benefit for pregnant women. Check with your insurance provider before your appointment.

How Do You Get the Vaccine?

If you want to get the RSV vaccine, you can:

Talk with your OB or midwife, ask about Abrysvo at your prenatal visit
Contact your pharmacy, many pharmacies offer the vaccine
Check with your insurance, confirm coverage before your appointment

What About Nirsevimab (Beyfortus)?

Nirsevimab is a long-acting monoclonal antibody given directly to the baby to protect against RSV. It is FDA-approved (under the brand name Beyfortus) and is available in the United States. A second long-acting infant antibody, clesrovimab, is also available.

The CDC recommends one of these antibodies for babies younger than 8 months who are born during or entering their first RSV season if the mother did not get the maternal RSV vaccine during pregnancy, if her vaccination status is unknown, or if the baby was born within 14 days of her vaccination. It is given shortly before RSV season, or within the first week after birth for babies born October through March in most of the US. Nirsevimab is also recommended for a small group of children aged 8 to 19 months who are at higher risk of severe RSV.

Most babies need either the maternal vaccine or the antibody shot, not both.

Frequently Asked Questions About the RSV Vaccine During Pregnancy

Is the RSV vaccine mandatory for pregnant women?

No, no vaccines are mandatory in the United States. The RSV vaccine is an option you can choose after speaking with your OB, midwife, or doctor. The CDC and AAP recommend that pregnant women consider the vaccine to protect their baby against serious RSV disease.

Can I get the RSV vaccine if I am allergic to eggs?

Abrysvo does not contain eggs or egg components, so egg allergy is not a contraindication. If you have known allergies, you should still inform your doctor before vaccination.

What if I give birth before two weeks have passed since the vaccine?

If your baby is born within 14 days of your RSV vaccine, the antibodies may not have had enough time to reach the baby. In that case the CDC recommends an RSV antibody shot for the baby, so ask your baby's doctor about it.

Can my partner get the RSV vaccine instead?

No, the RSV vaccine for pregnant women works by the mother transferring antibodies to the baby via the placenta. Partners cannot transfer antibodies this way. Abrysvo is also approved for adults 60 years and older for their own protection.

Does the RSV vaccine protect the baby against all colds?

No, the vaccine specifically protects against RSV (both subtypes A and B). It does not provide protection against other respiratory viruses such as rhinovirus, influenza, or coronavirus. However, RSV is the most important cause of serious lower respiratory tract infection in infants, so the vaccine targets the greatest threat.

Summary. Should You Get the RSV Vaccine?

The RSV vaccine (Abrysvo) is a relatively new option for pregnant women. The vaccine provides documented protection for newborns against serious RSV disease.

The CDC and AAP recommend that pregnant women discuss the vaccine with their OB or midwife. The benefit is clear protection of newborns during the most vulnerable period. The main things to plan are the timing (weeks 32 to 36, September through January in most of the US) and whether your baby will be protected by the vaccine or by an antibody shot after birth.

The most important thing you can do is bring it up with your healthcare provider at your next prenatal visit and make an informed decision together.

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RSV Vaccine During Pregnancy. What You Need to Know