Ask the Experts: RSV (Respiratory Syncytial Virus)

Results (77)

In the clinical trials of both RSVPreF3 (Arexvy, GSK) and RSVpreF (Abrysvo, Pfizer) vaccines, a small number of inflammatory neurologic events, including GBS, were reported after RSV vaccination. The degree to which RSV vaccination might increase the risk for inflammatory neurologic events is not yet fully understood. No cases of GBS or other inflammatory neurologic events were reported after mRNA RSV (mResvia) vaccination during the clinical trials. CDC and FDA are actively monitoring the safety of all of these vaccines through national safety surveillance systems in order to detect and estimate the magnitude of risks that are too small to be measured in clinical trials.

Last reviewed: August 25, 2024

In clinical trials, the vast majority of infants had no side effects detected after nirsevimab (Beyfortus, Sanofi) administration. The most common side effects noted during the clinical trials of nirsevimab were rash occurring within 2 weeks after injection (seen in 0.9% of nirsevimab recipients versus 0.6% of placebo recipients) and injection site reactions (including redness, pain, swelling) occurring within 7 days after injection (0.3% of nirsevimab recipients versus 0% of placebo recipients). See the product package insert for more details: www.accessdata.fda.gov/drugsatfda_docs/label/2023/761328s000lbl.pdf.

Last reviewed: August 25, 2024

Adverse reactions occurring after administration of nirsevimab (Beyfortus, Sanofi) alone should be reported to MedWatch online (www.fda.gov/medwatch), by fax, by mail, or by contacting FDA at 1-800-FDA-1088.

Adverse reactions occurring after the coadministration of nirsevimab with a vaccine should be reported to the Vaccine Adverse Event Reporting System (VAERS) https://vaers.hhs.gov, and reports should specify that the patient received nirsevimab on the VAERS form.

Last reviewed: August 25, 2024

Yes. V-safe is a vaccine safety monitoring system that lets recipients of certain new vaccines share with CDC how they feel after vaccination by receiving and responding to a series of periodic text messages. This is a voluntary system and individual recipients must register to participate V-safe. V-safe is available to Arexvy (GSK) and Abrysvo (Pfizer) RSV vaccine recipients.  At this time, V-safe is not being used for mResvia (Moderna) or for nirsevimab preventive antibody (Beyfortus, Sanofi). For information, or to register, visit CDC’s V-safe website at: www.cdc.gov/vaccine-safety-systems/v-safe/index.html.

Last reviewed: August 25, 2024

Nirsevimab (Beyfortus, Sanofi) is contraindicated in persons with a history of severe allergic reactions (e.g., anaphylaxis) after a previous dose or to a product component. As with any injection, when administering nirsevimab to children with increased risk for bleeding, providers should follow ACIP’s general best practice guidelines for immunization.

Last reviewed: August 25, 2024

RSV vaccines are contraindicated for and should not be administered to persons with a history of severe allergic reaction, such as anaphylaxis, to any component of the vaccine. People experiencing moderate or severe acute illness with or without fever should delay RSV vaccination until they are improved, as a precaution.

Last reviewed: August 25, 2024

Both protein-based vaccines (Abrysvo, Pfizer; Arexvy, GSK) are stored in the refrigerator. RSVPreF3 (Arexvy) is supplied as a single-dose vial of lyophilized antigen component (powder) and a single-dose vial of adjuvant suspension component (liquid). Both the liquid and the powder should be stored refrigerated between 2°C and 8°C (36°F and 46°F) in the original package in order to protect vials from light. Do not freeze. Discard if either component has been frozen.

After reconstitution, administer immediately or store in the refrigerator between 2°C and 8°C (36°F to 46°F) or at room temperature (defined for this vaccine as up to 25°C [77°F]) for up to 4 hours before use. Discard reconstituted vaccine if not used within 4 hours.

Last reviewed: August 25, 2024

Both protein-based RSV vaccines (Abrysvo, Pfizer; Arexvy, GSK) are stored in the refrigerator. RSVpreF (Abrysvo) is supplied in a kit that includes a vial of lyophilized antigen component (a white powder), a prefilled syringe with a sterile water diluent, and a vial adapter. Store at refrigerated temperatures between 2°C and 8°C (36°F and 46°F) in the original carton. Do not freeze. Discard if frozen. Follow reconstitution guidelines at www.fda.gov/media/168889/download.

After reconstitution, administer immediately or store at room temperature (defined for this vaccine as 15ºC to 30ºC [59°F to 86°F]) for up to 4 hours. Do not store reconstituted Abrysvo vaccine in the refrigerator or freezer. Discard reconstituted vaccine if not used within 4 hours.

Last reviewed: August 25, 2024

The mRNA RSV vaccine (mResvia, Moderna) is supplied as a manufacturer-filled syringe (MFS) that contains a frozen suspension that must be thawed before administration either in the refrigerator or at room temperature. Vaccine should not be refrozen once thawed. Do not shake any mRNA vaccine because shaking can damage the potency of the vaccine by breaking up the small bubbles of fat (lipid) that contain the mRNA.

  • Freezer storage: The frozen vaccine in the plastic MFS can be stored in the freezer between -40°C to -15°C (-40°F to 5°F) until the expiration date printed on its packaging.
  • Refrigerator storage: The thawed plastic MFS may be stored refrigerated between 2°C to 8°C (36°F to 46°F) for up to 30 days before being used. If stored in the refrigerator, place a label on the vaccine indicating when it was placed in the refrigerator and its ‘use by date’, which is 30 days later. Discard an MFS that has been in the refrigerator beyond its 30-day use-by date.
  • Room temperature storage: The thawed plastic MFS may be stored between 8°C to 25°C (46°F to 77°F) for a total of 24 hours after removal from refrigerated conditions. Discard the MFS if not used within this time. Do not return an MFS to the refrigerator after it has been thawed at room temperature.
  • Refer to the mResvia package insert for specific instructions and additional details on storage and thawing: www.fda.gov/media/179005/download.
Last reviewed: August 25, 2024

Nirsevimab (Beyfortus, Sanofi) comes in two single-dose manufacturer-filled syringe (MFS) formulations: 50-mg and 100-mg. Nirsevimab should be stored in the refrigerator between 36°F to 46°F (2°C to 8°C). It may be kept at room temperature 68°F to 77°F (20°C to 25°C) for a maximum of 8 hours. After removal from the refrigerator, nirsevimab must be used within 8 hours or discarded. Store nirsevimab in the original carton to protect it from light until time of use. Do not freeze. Do not shake. Do not expose to heat.

Last reviewed: August 25, 2024

No. Seasonal influenza vaccines are reformulated each year; for this reason, all unused seasonal influenza vaccines expire and should be discarded no later than the end of June each season. RSV products (vaccines and preventive antibody) do not change each season and products in your storage unit now may not expire until sometime during or after the next season.

Unless state or territorial public health authorities advise otherwise based upon local conditions, RSV vaccine should not be given during pregnancy after January. Likewise, nirsevimab (Beyfortus, Sanofi) should not be given to infants after March or before October unless specifically instructed by public health authorities.

Vaccination of eligible adults age 60 years or older will have the most benefit if RSV vaccine is administered in late summer or early fall, just before the typical RSV season. However, eligible adults may be vaccinated at any time of year if there is a need to vaccinate at other times of year. Vaccination is expected to provide meaningful protection from serious RSV disease for 2 years or longer. Only one dose of RSV vaccine is recommended: revaccination is not recommended.

Properly store and clearly label unexpired products remaining in your storage unit during periods when they are not in use and train staff on the timing of these products, especially for vaccination during pregnancy and use of nirsevimab. Consider storage and labeling that minimizes the risk of mishandling or administration outside the times when the product is recommended to be used.

Last reviewed: August 25, 2024


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Last reviewed: June 7, 2024

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