Maternal RSV Vaccination

RSV is a common respiratory virus that usually causes mild cold-like symptoms. Most people recover in a week or two, but RSV can cause a serious illness in some groups, including infants and older adults. Here are some key data points:

• RSV is one of the most common causes of childhood respiratory illness.

• RSV is the leading cause of hospitalization for infants in the United States. An estimated 58,000–80,000 children under five years old, most of them infants under six months old, are hospitalized each year nationwide because of RSV infection. 

• Each year, an estimated 100–300 children younger than five years old die because of RSV in the United States.

Currently the only RSV vaccine product approved and recommended for use in pregnant individuals is Pfizer’s RSVpreF vaccine (Abrysvo).

The following vaccines are not approved for use in pregnancy: GSK’s RSV vaccine Arexvy, and Moderna’s RSV vaccine MRESVIA.

Patients should be counseled about both the RSV vaccine during pregnancy and the monoclonal antibody nirsevimab for the baby after birth as safe and effective options for the prevention of RSV lower respiratory tract infections in infants younger than 6 months old. (See below for more information on counseling patients.)

ACOG and CDC recommend a single dose of Pfizer’s RSV vaccine (Abrysvo) for eligible pregnant individuals between 32 0/7 and 36 6/7 weeks of gestation who do not have a planned delivery within two weeks, using seasonal administration, to prevent RSV lower respiratory tract infection in infants. 

The monoclonal antibody product nirsevimab is recommended for newborns and young infants whose mothers did not receive the RSV vaccine during the current or any previous pregnancy or who were born within 14 days of maternal receipt of the RSV vaccine. 

Eligible individuals are those who are currently pregnant if they are between 32 0/7 and 36 6/7 weeks of gestation this respiratory virus season, who do not have a planned delivery within two weeks, and who did not receive the maternal RSV vaccine during RSV season.

It is currently not recommended that pregnant patients who received the maternal RSV vaccine during the previous RSV season receive an additional dose during the next respiratory virus season. For patients vaccinated in a previous pregnancy, their infants should receive nirsevimab during the respiratory virus season.

Pregnant patients who receive the RSV vaccine during pregnancy should be encouraged to participate in V-safe.

Pregnant patients should be counseled about RSV and the risk of infection to their newborns and young infants. All infants are recommended to be protected from severe RSV disease by either the maternal RSV vaccine or nirsevimab for the RSV season. Clinicians should counsel patients about the benefits of maternal RSV vaccination as a safe and effective way to prevent severe lower respiratory tract illness caused by RSV in newborns through infants age 6 months. Clinicians should also counsel patients regarding nirsevimab as a safe and effective option for newborns if the maternal RSV vaccine is not received during pregnancy or if the patient was previously vaccinated during pregnancy.

Clinicians should also explain the difference between RSV, influenza, and COVID-19 and the need for different vaccines to protect against each of these infections.

See ACOG’s Practice Advisory and Seven Things to Share with Your Patients About the Maternal RSV Vaccine for additional counseling considerations. 

Yes, the RSV vaccine is a safe option during pregnancy for the prevention of RSV lower respiratory tract infection in infants. 

The clinical trial for the RSV vaccine (the MATISSE trial) was a multi-country randomized clinical trial comparing the RSVpreF vaccine to placebo administered in pregnancy in over 7,000 participants. Vaccine recipients in the study experienced typical side effects including pain at the injection site, headache, muscle pain, and nausea. A numerical imbalance in preterm births in vaccine recipients (5.7%) occurred compared to those who received placebo (4.7%). This imbalance was not statistically significant and was seen most often in trial participants residing in low- to middle-income countries. Thus, the available data are insufficient to establish or exclude a causal relationship between maternal RSV vaccination and preterm birth. However, to mitigate the theoretical risk of preterm birth, RSV vaccine should be administered to pregnant individuals at 32 through 36 weeks of gestation.

Pregnant patients who receive the RSV vaccine during pregnancy should be encouraged to participate in V-safe.

Adverse events should be reported to the Vaccine Adverse Event Reporting System (VAERS).

Most infants born to people who were vaccinated during pregnancy do not need to receive the monoclonal antibody immunization nirsevimab. There are some exceptions, and infants may receive nirsevimab based on the health care professional’s clinical judgment and patient preferences if …

• The pregnant person received the maternal RSV vaccine during the previous RSV season

• The pregnant person’s RSV vaccine status during the current pregnancy is unknown

• The pregnant person delivers within 14 days of receipt of maternal vaccination

• The infant might have experienced loss of transplacentally acquired antibodies (eg, those who have undergone cardiopulmonary bypass or extracorporeal membrane oxygenation)

• The infant has substantially increased risk for severe RSV disease

• The pregnant person may not mount an adequate immune response to vaccination (eg, people with immunocompromising conditions) or has conditions associated with reduced transplacental antibody transfer (eg, people living with HIV infection)

RSV vaccination or declination during pregnancy should be clearly documented in the patient’s medical chart and communicated to the newborn’s clinician.

There are no head-to-head studies comparing the efficacy of maternal vaccination to the efficacy of newborn or infant monoclonal antibody immunization. Each prevention measure has been shown to be safe and effective in their respective clinical trials. Thus, the decision to receive the vaccine or wait for the monoclonal antibody after birth should be based on patient preference after a conversation between the patient and health care professional. Considerations to discuss include the following:

• Patient’s vaccination status with the maternal RSV vaccine

• The availability of the monoclonal antibody nirsevimab*

• The availability of the RSV vaccine

• The patient’s preference for maternal vaccination or monoclonal antibody immunization

• The patient’s current health conditions and circumstances

See ACOG’s Practice Advisory for additional counseling considerations.

* If supply of nirsevimab is limited in the future, this could be a key component of conversations and decision making with patients regarding maternal vaccination. Maternal vaccination should be encouraged, particularly in areas where nirsevimab is limited or unavailable.

Yes. It is critically important that pregnant patients receive all recommended vaccines. Maternal RSV vaccine can be safely administered at the same time as other vaccines routinely recommended during pregnancy, including influenza, Tdap, and COVID-19 vaccines.

It is currently not recommended that pregnant patients who received the maternal RSV vaccine during the previous RSV season receive an additional dose during a subsequent pregnancy. For patients vaccinated in a previous pregnancy, their infants should receive nirsevimab during the current respiratory virus season. There are currently no safety or efficacy data to inform recommendations related to RSV vaccination in subsequent pregnancies. Data are needed to determine whether additional seasonal doses during subsequent pregnancies are necessary and safe, and as these data become available, the Advisory Committee on Immunization Practices may update recommendations.

Only singleton pregnancies were included in the clinical trials for RSV vaccine. However, assuming the babies are born at least 14 days after maternal receipt of the RSV vaccine and no other risk factors are present, the monoclonal antibody should not be necessary.

Yes. Recent RSV infection is not a contraindication to vaccination. There is no specific length of time that pregnant patients need to wait after having RSV exposure or infection before pregnant people can receive an RSV vaccine within the indicated window. 

In most cases, yes.

• Medicaid is required to cover the RSV vaccine in all states with no out-of-pocket costs for nearly all full-benefit adult beneficiaries with traditional Medicaid.

• Pregnant patients eligible for the Vaccines for Children (VFC) program will be covered with no out-of-pocket costs but must receive the vaccine from a participating VFC health care professional. Check with local pharmacies to confirm if they participate in the VFC program before scheduling a vaccine appointment.

• Most private insurers are required to cover the vaccine. This barrier should be minimal given it is at least one year since the original recommendation.

• Patients should check with their insurance plan about vaccine coverage. If planning to receive the vaccine at a pharmacy, they should confirm the pharmacy is in-network to minimize out-of-pocket costs.

• To facilitate access to Abrysvo during the RSV maternal vaccination season, ensure patients meet eligibility requirements (gestational age and seasonal window). Include all required codes on the claim (e.g., gestational age, CPT for visit, and administration of Abrysvo) and confirm billing requirements with payers, as they may vary.

For more information on RSV vaccine coverage, see ACOG’s information on new CPT codes for RSV vaccine administration and immunization coding for ob-gyns.

Yes. Many pharmacies are offering the RSV vaccine to pregnant patients. If you are referring your patient to a pharmacy, here are some key considerations and tips:

• Identify nearby pharmacies that carry Pfizer’s RSVpreF vaccine, Abrysvo, so you can ensure patients are sent to a location with the correct vaccine. The other RSV vaccine products, Arexvy and mResvia, are not approved for use in pregnant people.

• Encourage patients to check their pharmacy’s website to see if an appointment is recommended for vaccine visits. For most pharmacies, vaccine appointments are strongly recommended, but walk-ins are usually accommodated.

• Pharmacists’ authority to administer different types of vaccines varies by state.

• Remind patients to confirm they are between 32 0/7 and 36 6/7 weeks of gestation when presenting to the pharmacy. Clinicians can provide patients with an after-visit summary with this information.

Most states do not require a prescription for vaccines administered to adults at pharmacies. However, it is helpful to check if local pharmacies require a prescription for the maternal RSV vaccine.

• You can find information on pharmacist authority, including prescription requirements, through the American Pharmacists Association website’s immunization information center.

• If a prescription is required, include the indication “due to pregnancy” on the prescription, confirm the patient is between 32 0/7 and 36 6/7 weeks of gestation, and specify “Pfizer Abrysvo.”

Documentation of vaccine receipt or declination is an essential component of any immunization program. All vaccines received or declined should be documented in the patient’s chart and state immunization information system. 

This is particularly important for maternal RSV vaccination because most infants of people who received maternal RSV vaccine are not recommended to receive nirsevimab. 

As such, clinicians should document receipt or declination of maternal RSV vaccination in the patient’s medical chart and encourage the patient to share this information with their child’s pediatrician during their first visit. One tip is to encourage the parent to take a photo of the document for later sharing. Hospitals and pediatric care professionals will need to know the maternal RSV vaccination status to counsel patients appropriately about the monoclonal antibody nirsevimab for the newborn.

The CDC recommends that all newborns under eight months old receive RSV immunization if the gestational parent’s RSV vaccine status is unknown. Sharing documentation will help infants avoid an unnecessary immunization.  

For more information on documentation and coding, please see ACOG’s New CPT Codes for RSV Vaccine Administration and Immunization Coding for Obstetrician–Gynecologists.