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Healthcare Providers: RSV Vaccination for Pregnant People
Composition of RSVpreF vaccine (Abrysvo, Pfizer)
RSVpreF (Abrysvo, Pfizer) consists of a recombinant RSV F protein antigen (based on both the RSV-A and RSV-B subtypes), stabilized in the prefusion conformation (preF). The vaccine is supplied as a single-dose vial of 120 μg of lyophilized preF antigen component (60 μg from RSV-A, 60 μg from RSV-B) to be reconstituted with the accompanying vial of sterile water diluent component. A single dose after reconstitution is approximately 0.5 mL. Consult the package insert for proper storage and handling details, shelf life, and reconstitution instructions: Package Insert – ABRYSVO (fda.gov).
Storage and handling of RSVpreF vaccine (Abrysvo, Pfizer)
Proper vaccine storage and handling practices play an important role in protecting individuals and communities from vaccine-preventable diseases. For general recommendations and guidance, see Vaccine Storage and Handling. Provided below is guidance for the RSVpreF vaccine.
Pfizer’s vaccine is supplied in a kit with three components:
- Vial of Lyophilized Antigen Component (a sterile white powder)
- Prefilled syringe containing Sterile Water Diluent Component
- Vial adapterRefer to the manufacturer’s package insert for specific instructions on reconstituting the vaccine: Package Insert – ABRYSVO (fda.gov).
Before reconstitution:
- Store vaccine and diluent refrigerated between 2°C and 8°C (36°F and 46°F).
- Store these components in their original package and keep them together in the refrigerator to optimize organization.
- Never freeze the vaccine or diluent.
After reconstitution:
- Immediately administer the vaccine; you should prepare the vaccine only when ready for use. If you do not immediately administer the vaccine, there are some minor differences in storage:
- Store the reconstituted vaccine ONLY at room temperature (15⁰C to 30⁰C / 59⁰F to 86⁰F).
- Do NOT refrigerate. This is very different than other reconstituted vaccines. Typically, storage after reconstitution is refrigerated storage only or refrigerated or room temperature storage. For this vaccine, do NOT put it back in the refrigerator.
- Never freeze the vaccine or diluent.
- Once you’ve reconstituted the vaccine, you begin a 4-hour beyond-use date clock. This means that you must use the reconstituted vaccine within 4 hours; otherwise discard it.
Administering RSVpreF vaccine (Abrysvo, Pfizer)
This page provides a summary of guidance for administering RSVpreF vaccine (Abrysvo, Pfizer) for use in pregnant people, including route, number of doses, and co-administration with other vaccines.
Do not use RSVpreF vaccine (Abrysvo, Pfizer) beyond the expiration date printed on the label.
Route
Administer RSVpreF vaccine (Abrysvo, Pfizer) intramuscularly. The preferred site of administration is the deltoid region of the upper arm. Do not administer RSV vaccine intravenously, intradermally, or subcutaneously.
Number of Doses
RSVpreF vaccine (Abrysvo, Pfizer) is currently approved and recommended for administration as a single dose. Sufficient evidence does not exist at this time to determine the need for additional doses in subsequent pregnancies.
Administration with other vaccines
Pregnant people can receive RSV, Tdap, COVID-19, and influenza vaccines at the same clinic visit when the vaccines are recommended. CDC’s general best practice guidelines for immunization indicate that age-appropriate vaccinations can be given at the same visit, unless there is a specific reason not to.
Administration Errors
Pfizer’s Abrysvo is the only RSV vaccine recommended for pregnant people. GSK’s Arexvy and Moderna’s mResvia are not approved for use in pregnancy. If a pregnant person receives Arexvy or mResvia in error, the following guidance is provided:
- For pregnant people who have received Arexvy or mResvia in error, do not give the pregnant person a dose of the Pfizer RSV vaccine (Abrysvo).
- Inform the recipient of the vaccine administration error.
- Experts suggest no special monitoring for the pregnant person beyond routine prenatal care is needed.
- If Arexvy or mResvia is given in error to a pregnant person, the infant should receive nirsevimab for RSV prevention.
- Providers should consult with the state immunization program and/or immunization information system (IIS) to determine how the dose should be entered into the IIS.
- Determine how the error occurred and implement strategies to prevent it from happening again. Potential strategies to help prevent these errors include:
- Order and stock vaccine products that fit best with your patient population. Avoid stocking both products, if possible.
- If both RSV vaccine products are stocked, label the Arexvy (GSK) vaccine “Do NOT administer to pregnant people.”
- Educate staff on vaccine recommendations. If both RSV products are stocked, train staff about the differences in preparation and indications.
- Follow medication administration best practices – read and check the vaccine product label at least 3 times and ask another staff member to confirm that it is the correct vaccine product for the patient.
- If referring pregnant people to another vaccine provider, tell the provider to administer Abrysvo (Pfizer) vaccine and to confirm the vaccine product prior to administration.
- Healthcare providers are encouraged to report this event to the Vaccine Adverse Event Reporting System (VAERS), even if there is no adverse health event associated with the error.
References and Resources
- Food and Drug Administration: FDA Approves First Vaccine for Pregnant Individuals to Prevent RSV in Infants. Press Release. Silver Spring, MD: US Department of Health and Human Services, Food and Drug Administrations; 2023. https://www.fda.gov/news-events/press-announcements/fda-approves-first-vaccine-pregnant-individuals-prevent-rsv-infants
- Food and Drug Administration. ABRYSVO package insert. Silver Springs, MD: US Department of Health and Human Services, Food and Drug Administrations; 2023. https://www.fda.gov/media/168889/download?attachment
- Kampmann B, Madhi SA, Munjal I, et al. Bivalent Prefusion F Vaccine in Pregnancy to Prevent RSV Illness in Infants. N Engl J Med. 2023 Apr 20; 388(1):1451–1464. doi:10.1056/NEJMoa2216480.
- Hamid S, Winn A, Parikh R, et al. Seasonality of Respiratory Syncytial Virus – United States, 2017-2023. MMWR Morb Mortal Wkly Rep. 2023 Apr 7;72(14):355-361. doi: 10.15585/mmwr.mm7214a1
- CDC RSV Surveillance & Research