Issue 1741: February 15, 2024

Ask the Experts: Answers Questions about RSV Immunization (Part 2)

As an additional service to IZ Express readers, we periodically publish special editions such as this one, providing you with new and updated Ask the Experts questions and answers from experts. This issue, the second of two special editions focused on RSV vaccines and preventive antibody, includes 13 Q&As based on CDC clinical guidance about adult and infant RSV immunization timing, documentation, and administration. 
To find the full set of's Ask the Experts RSV Q&As, visit
You can find all of these questions and answers, plus more than 1,300 others about vaccines and vaccine administration, on our "Ask the Experts" main page at's team of experts includes Kelly L. Moore, MD, MPH (team lead), Carolyn B. Bridges, MD, FACP, and Iyabode Beysolow, MD, MPH.
RSV Vaccines
RSV Preventive Antibody (Nirsevimab)

RSV Disease

Q: How often should the RSV vaccine be given?

A: Both RSV vaccines are currently licensed and recommended as a one-time dose for any person; data are not available at this time to make recommendations for revaccination. At this time, a pregnant person who receives Abrysvo during one pregnancy is not recommended to receive Abrysvo during a subsequent pregnancy. ACIP will make decisions concerning revaccination as more data become available.

Q: Is Abrysvo RSV vaccine in the Vaccines For Children (VFC) program?

A: Yes. VFC-eligible pregnant adolescents younger than age 19 may receive VFC-funded Abrysvo during pregnancy, if indicated, in VFC-participating facilities. Contact your state immunization program with questions about VFC and Abrysvo.

Q: Can RSV vaccine be administered at the same time as other vaccines?

A: Yes. It is acceptable to administer either RSV vaccine at the same time as other recommended vaccines, in accordance with CDC’s general best practice guidelines for immunization. This is especially important if you are concerned an unvaccinated patient will not return or if the patient’s immediate risk is high (such as when seasonal influenza, RSV, and COVID-19 are circulating). Coadministration might increase short- term side effects (greater reactogenicity), such as fever, soreness, body aches, or headache, especially when administering more than one vaccine containing a non-aluminum adjuvant designed to enhance the immune response. While these side effects are not unsafe, they may be unpleasant for a day or two. If you are confident that a patient will return, the patient may prefer to separate the administration of vaccines that are less time-sensitive (e.g., shingles vaccine) to reduce the likelihood of uncomfortable side effects. There is no specific minimum interval between non-live vaccines, so separation by just a few days is acceptable, if desired.

Q: When is the best time of year to administer the RSV vaccine to an older adult?

A: Optimally, vaccination of eligible adults should occur before the onset of increased RSV activity in the community. The timing of the onset, peak, and decline of RSV activity varies from one year to the next; however, because the vaccine’s protection in older adults lasts at least 2 seasons, if you have the opportunity to vaccinate during the summer, you might choose to give it if you are concerned that you may not have the opportunity later in the fall.

Q: How can I ensure that a child’s pediatrician is aware of the mother’s RSV vaccination status?

A: It is important that all healthcare providers, both prenatal and pediatric, ensure that maternal RSV vaccination status is clearly documented and communicated. Prenatal care providers and birthing hospitals should ensure maternal RSV vaccination is reported to state immunization information systems (registries) and documented in maternal and newborn health records. It is also important to provide the pregnant person with a personal record of immunization.
Failure to document and communicate maternal RSV vaccination may result in extra work for pediatric offices and families to obtain records or in unnecessary administration of nirsevimab, at a retail cost of approximately $450 per dose.

Q: An error was made resulting in an infant receiving RSV vaccine instead of the nirsevimab RSV preventive antibody. What should be done?

A: The safety and effectiveness of RSV vaccines have not been studied in infants. The family should be informed of the error, and nirsevimab should be administered as recommended as soon as feasible. CDC experts recommend that if you administer nirsevimab within 72 hours of the error, and you know where the RSV vaccine was injected, you should administer the nirsevimab in a different anatomic site. Facilities that stock RSV vaccine and nirsevimab should put systems and procedures in place to prevent this type of error, including staff training, clear labeling, and warnings in storage units. This medication error and any suspected adverse events following the error should be reported to the Vaccine Adverse Event Reporting System (VAERS) at
For additional information about this type of error, see CDC’s COCA Now: Clinician Outreach Communication Activity update, dated January 22, 2024, at
CDC has developed a job aid to help clinical staff reduce the risk of administration errors related to RSV vaccines and nirsevimab:

RSV Preventive Antibody and Infants

Q: Nirsevimab isn’t a vaccine, so do I give a VIS for nirsevimab? 

A: CDC has published an immunization information statement (IIS) for nirsevimab that is the equivalent of the vaccine information statement (VIS) for vaccines. Just as with a VIS, providers should give the IIS to the parent or caregiver before immunization and document it in the medical record.
Access the current nirsevimab IIS and translations in at least 24 languages from at:

Q: Is nirsevimab available through the Vaccines For Children (VFC) program?

A: Yes, it is. Infants and toddlers eligible for the VFC program may receive nirsevimab when recommended in the same way and in the same facilities where they receive VFC vaccines. Providers who participate in VFC should follow all VFC requirements for ordering, storage, and administration established by their state immunization program.

Q: My patient’s mother was vaccinated for RSV at 33 weeks’ gestation but delivered the baby a week later. It is now January. Does this infant need nirsevimab?

A: Yes. Infants born less than 14 days after the mother received RSV vaccine should receive nirsevimab. Infants born within 14 days after maternal vaccination may not have had sufficient time in utero to receive adequate protection from maternal RSV antibodies produced after vaccination. Infants born 14 days or more after maternal vaccination are not recommended to receive nirsevimab. 

Q: Can nirsevimab be coadministered with vaccines?

A: Yes, nirsevimab may be coadministered with all other recommended age-appropriate vaccines. Nirsevimab should not interfere with the immune response to routine childhood vaccines when given together or at any time before or after them. Likewise, vaccination does not interfere with the effectiveness of nirsevimab.
When giving several injections at a single visit, separate intramuscular vaccines by at least 1 inch in the body of the muscle, if possible, to reduce the likelihood of overlapping local injection site reactions. 

Q: A 65-year-old adult was inadvertently administered a dose of nirsevimab preventive antibody for infants. What do we do?

A: The recipient should be informed of the error, and RSV vaccine should be administered as recommended. A 50-mg or 100-mg MFS dose of antibody is very small compared to the body weight of an adult and you should not assume the dose would have any protective effect. There is no defined waiting period after antibody administration for vaccine administration. Facilities that stock RSV vaccine and nirsevimab should put systems and procedures in place to prevent this type of error, including staff training and clear labeling and warnings in storage units.

CDC strongly encourages reporting of this medication error and any suspected adverse events following the error to the Vaccine Adverse Event Reporting System (VAERS) at if the antibody was administered at the same visit as vaccines. If antibody was administered alone, report the incident to MedWatch online (, by fax, by mail, or by contacting FDA at 1-800-FDA-1088.
CDC has developed a job aid to help clinical staff reduce the risk of administration errors related to RSV vaccines and nirsevimab:

Q: A 2-week-old infant whose mother had limited prenatal care is a new patient. The mother might have had RSV vaccine, but we can’t be sure. What do we do?

A: If you are unable to obtain prenatal records or verify receipt of maternal RSV vaccine, CDC recommends that the baby receive nirsevimab, particularly if it is shortly before or during the RSV season. Don’t forget to check the state immunization information system (IIS) for the mother’s vaccination record. It is also important to attempt to verify from the birthing facility records whether this baby received nirsevimab prior to discharge to avoid giving a second dose.

Q: When is the optimal timing for infants and toddlers to receive nirsevimab?

A: Aim for nirsevimab administration in the first week of life for infants born shortly before or during the RSV season (typically October through March). Infants with prolonged birth hospitalizations due to prematurity or other causes should receive nirsevimab shortly before or promptly after discharge.
Infants younger than age 8 months born outside of the RSV season and older infants or toddlers at high risk who are recommended to receive nirsevimab in their second RSV season, should aim to receive nirsevimab shortly before the start of the RSV season (typically October).
If the ideal timing is missed, age-eligible infants and children who have not yet received a dose may be immunized at any time during the RSV season.

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Editorial Information

  • Editor-in-Chief
    Kelly L. Moore, MD, MPH
  • Managing Editor
    John D. Grabenstein, RPh, PhD
  • Associate Editor
    Sharon G. Humiston, MD, MPH
  • Writer/Publication Coordinator
    Taryn Chapman, MS
    Courtnay Londo, MA
  • Style and Copy Editor
    Marian Deegan, JD
  • Web Edition Managers
    Arkady Shakhnovich
    Jermaine Royes
  • Contributing Writer
    Laurel H. Wood, MPA
  • Technical Reviewer
    Kayla Ohlde

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