Abrysvo

Pronunciation: uh-breez-voh
Generic name: respiratory syncytial virus vaccine [ RSVpreFa/preFb-recombinant ]
Dosage form: Act-O-Vial for reconstitution (0.5 mL), vial and prefilled syringe (0.5 mL), vial and vial (0.5 mL)
Drug class: Viral vaccines

Medically reviewed by Carmen Pope, BPharm. Last updated on June 19, 2025.

What is Abrysvo?

Abrysvo is a vaccine used to prevent respiratory syncytial virus (RSV) lower respiratory tract disease (LRTD, lung infections) in pregnant women (32 through 36 weeks of gestation), adults 60 years and older, and adults aged 18 through 59 years at increased risk for LRTD caused by RSV. It is administered as a single intramuscular (IM) injection.

• RSV season is usually late fall (November) through spring (April), with a peak in January and February.
• Abrysvo may be given at any time of the year, but where possible, should be offered before the start of the RSV season.
• Only one dose of Abrysvo is needed. It is not given every RSV season.

Abrysvo works by stimulating the immune system to produce antibodies against RSV's prefusion F protein, preventing respiratory disease. When given to pregnant women, these antibodies cross the placenta, providing passive immunity that protects newborns under 6 months from severe RSV infections. Abrysvo belongs to the drug class called RSV vaccines.

• Abrysvo is the only RSV vaccine approved for use during pregnancy.

Abrysvo first gained FDA approval on May 31, 2023, for adults aged 60 and older. This approval was extended twice to include pregnant women and adults aged 18 through 59. Approvals were based on positive results from three clinical trials:

• RENOIR (Phase 3 RCT, NCT05035212, n=34,284 adults ≥60 years): Abrysvo showed 66.7% efficacy against RSV lower respiratory tract illness with two+ symptoms and 85.7% efficacy with three+ symptoms. Local reactions were higher with the vaccine (12%) versus placebo (7%), but serious adverse events were similar
• MATISSE (Phase 3 trial, NCT04424316, n=7,000+ pregnant women). Vaccination showed 81.8% efficacy against severe RSV in infants within 90 days and 69.4% efficacy through six months, with a good safety profile
• MONeT (Phase 3 RCT, NCT05842967, n=687 adults aged 18-59 years at high risk of severe RSV disease). Showed safety and immunogenicity. 

FDA approvals and uses

Abrysvo is a vaccine approved for active immunization of:

• Pregnant women at 32 through 36 weeks of gestational age for the prevention of LRTD and severe LRTD caused by RSV in infants from birth through 6 months of age
• Adults 60 years and older for the prevention of LRTD caused by RSV
• Adults aged 18 through 59 years at increased risk for LRTD caused by RSV. Examples of medical conditions that may put someone at increased risk of LRTD include diabetes, cardiovascular disease, respiratory disease, or diabetes.

Side effects

The most common side effects of Abrysvo in pregnant women are:

• pain at the injection site
• headache
• muscle pain
• nausea.

The most common side effects of Abrysvo in adults 60 and older are:

• fatigue
• headache
• pain at the injection site
• muscle pain.

The most common side effects of Abrysvo in adults aged 18 through 59 are:

• pain at the injection site
• muscle pain
• joint pain
• nausea.

Serious side effects and warnings

Abrysvo may cause the following serious side effects:

• Guillain‑Barré Syndrome. Postmarketing reports suggest an increased risk of Guillain‑Barré syndrome developing within 42 days of vaccination with Abrysvo. This is a condition in which the body's immune system attacks the nerves. Seek urgent medical attention for symptoms such as weakness or tingling in your legs that may spread to your upper body and arms, muscle weakness, or difficulty breathing, swallowing or speaking.
• Potential risk of preterm birth. Abrysvo may increase the risk of having your baby too early (preterm). To lessen this potential risk, Abrysvo should not be administered to pregnant women before 32 weeks of gestation. It should only be administered from 32 weeks through 36 weeks gestational age. 
• Allergic reactions. Vaccinations may cause allergic reactions, including anaphylaxis, in some people. These usually happen within the first few minutes after an injection. Abrysvo vaccine should be administered in a facility that can provide the appropriate medical treatment and supervision to manage possible anaphylactic reactions following administration. Tell your healthcare provider if you have ever reacted to a vaccine. See urgent medical attention if you develop facial or throat swelling, a dry cough, a rash, or difficulty breathing.
• Fainting may occur following the administration of vaccines, such as Abrysvo vaccine. Sit or lie down during the vaccination to avoid injury from fainting.

People who are immunocompromised, including those receiving immunosuppressive therapy, may have a diminished immune response to vaccines.

Vaccination with Abrysvo may not protect everybody who receives it.

Abrysvo is not approved for use in children.

These are not all the side effects of Abrysvo. Report all side effects to your healthcare provider or to the Vaccine Adverse Event Reporting System at 1-800-822-7967 and www.vaers.hhs.gov.

Related/similar drugs

Before receiving

Do not receive an Abrysvo vaccine if you have a history of severe allergic reactions (such as anaphylaxis) to RSV vaccines, Abrysvo, or any of its inactive ingredients.

Before receiving Abrysvo tell your healthcare provider about all your medical conditions, including if you:

• have bleeding or bruising problems
• are prone to fainting after a vaccination
• are younger than 18 years and not pregnant
• are pregnant or intending to become pregnant
• are breastfeeding.

How do I receive Abrysvo?

Abrysvo is given by intramuscular injection, usually into the deltoid muscle of the upper arm.

• A single dose is given.

Abrysvo is given to pregnant women from 32 weeks through 36 weeks gestation.

Dosing information

Dose of Abrysvo for pregnant women (32-36 weeks) and adults 18 years and older

• 0.5 mL

Abrysvo ingredients

Active ingredients: 120 mcg of RSV stabilized perfusion F proteins (60 mcg RSV preF A and 60 mcg RSV preF B) per 0.5 mL.

Inactive ingredients: 0.11 mg tromethamine, 1.04 mg tromethamine hydrochloride, 11.3 mg sucrose, 22.5 mg mannitol, 0.08 mg polysorbate 80, and 1.1 mg sodium chloride per 0.5 mL.

Contains no preservatives.

The Act-O-Vial stoppers, vial stoppers and tip cap and rubber plunger of the prefilled syringe are not made with natural rubber latex.

Who makes Abrysvo?

Abrysvo is manufactured by Pfizer Inc. and distributed by Pfizer Labs, located in New York, NY 10001.

Abrysvo Biosimilars

Biosimilar and interchangeable products are biological products that are highly similar to and have no clinically meaningful differences from the reference product.

Reference products

These are biological products that have already been approved by the FDA, against which biosimilar products are compared. There is 1 for Abrysvo.

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Further information

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