Abrysvo is an RSV vaccine that is used to immunize pregnant women and adults aged 60 years and older. Abrysvo protects against developing lower respiratory tract disease (LRTD) caused by the respiratory syncytial virus (RSV) for the adults treated, and by vaccinating pregnant women, it protects infants against LRTD from birth through 6 months of age. Abrysvo works by developing immunity against two RSV proteins (antigens) RSVpreF A and RSVpreF B, so that if you get RSV, the infant or adult's immune system will be able to recognize it and destroy it.

RSV is a common, contagious virus that can cause hospitalization and death in patients that are at high risk for severe disease, which includes infants and older adults with underlying medical conditions such as diabetes and chronic heart and lung diseases.

Abrysvo became FDA-approved for adults aged 60 years and older on May 31, 2023. Abrysvo became the first RSV vaccine to be FDA-approved for pregnant women on August 21, 2023. It can be used between 32 through 36 weeks gestational age of pregnancy. It was approved for pregnant women after positive results from the Phase 3 clinical trial (NCT04424316) MATISSE (MATernal Immunization Study for Safety and Efficacy).

How well does Abrysvo work?

When used in pregnant women, Abrysvo reduced the risk of severe lower respiratory tract disease in infants by 81.8% within 90 days after birth and 69.4% within 180 days after birth. In older adults, the vaccine showed 67% efficacy in reducing the risk of developing RSV-associated lower respiratory tract disease with 2 or more symptoms and 86% efficacy in reducing the risk of developing RSV-associated LRTD in those with 3 or more symptoms.

Possible anaphylactic reactions

Administer in a facility that can provide the appropriate medical treatment and supervision to manage possible anaphylactic reactions following administration.

For pregnant individuals

To avoid the potential risks of preterm birth, vaccination should be given during 32 through 36 weeks of gestational age.

In clinical trials where Abrysvo was compared to placebo, infants born to pregnant individuals experienced low birth weight (5.1% Abrysvo compared to 4.4% placebo) and jaundice (7.2% Abrysvo compared to 6.7% placebo)

Syncope (fainting)

Fainting may occur following the administration of vaccines. Procedures should be in place to avoid injury from fainting.

Immunosuppression

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

Limitations

Vaccination may not protect all vaccine recipients.

Children

Abrysvo is not approved for children.

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

The dose is 0.5mL.

Do not administer the vaccine to anyone with a known history of severe allergic reactions (such as anaphylaxis) to Abrysvo or any of its components.

Abrysvo is generally well tolerated, and the most common side effects included fatigue, headache, injection site pain, and muscle pain. These were generally only short-lived.