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Two syringes with a "vs." between them: Abrysvo vs. Arexvy: Differences, similarities & side effects
Drug vs. Drug

Abrysvo vs. Arexvy: Differences, similarities & side effects

Everything you need to know about these two RSV vaccines
Gerardo Sison medical writer headshot
By | Jun. 6, 2024

Key takeaways

  • Arexvy and Abrysvo are FDA-approved vaccines used to prevent severe RSV infections in adults over 60, with Abrysvo also approved for use in late-stage pregnancy.

  • Abrysvo, lacking an adjuvant, is designed to protect against both RSV A and B strains, while Arexvy includes an adjuvant to boost the immune response, potentially making it more suitable for older adults with weakened immune systems.

  • Both vaccines share common side effects, including injection site pain and fatigue, but unlike Arexvy, Abrysvo may also cause nausea and diarrhea.

In this article:

Respiratory syncytial virus (RSV) is a common respiratory virus that typically causes mild, cold-like symptoms but can be severe in infants and older adults. In some cases, RSV-related infections may lead to hospitalization or death. In response to this health concern, two brand-name vaccines, Arexvy and Abrysvo, have recently become available as preventive measures. They work by stimulating the body’s immune response to defend against RSV.

These vaccines are designed for adults over the age of 60, a demographic vulnerable to severe RSV infections. Arexvy and Abrysvo serve the same goal but vary in how they are made and given. They may also vary in potential costs and side effects. Therefore, it’s important to discuss your options with a healthcare provider. 

Read on to learn more about the similarities and differences between Abrysvo and Arexvy. 

Abrysvo vs. Arexvy: Key differences

The key differences between the two vaccines lie in their composition. Abrysvo, developed by Pfizer Inc., is a bivalent vaccine that does not contain an adjuvant but is designed to protect against both strains of the virus, RSV A and RSV B. The lack of an adjuvant means that this vaccine uses the antigens themselves to evoke an immune response. 

Arexvy, on the other hand, is an adjuvanted vaccine developed by GlaxoSmithKline (GSK). An adjuvanted vaccine contains a substance that helps boost the immune response to the vaccine. This can be particularly helpful for older adults whose immune systems may not work as effectively.

 

Abrysvo vs. Arexvy: Compare key differences
Abrysvo Arexvy
Drug class Respiratory syncytial virus (RSV) vaccine Respiratory syncytial virus (RSV) vaccine, adjuvanted
Brand/generic status Brand Brand
What is the generic name? RSVPreF vaccine RSVPreF3 vaccine
What form(s) does the drug come in? Intramuscular injection Intramuscular injection
What is the standard dosage? A single dose of 0.5 ml into the muscle A single dose of 0.5 ml into the muscle
How long is the typical treatment? One dose One dose
Who typically uses the medication? Adults 60 years and older, pregnant women at 32 through 36 weeks of pregnancy Adults 60 years and older

 

Abrysvo vs. Arexvy: Conditions treated

Abrysvo and Arexvy are two vaccines approved by the Food and Drug Administration (FDA) to protect individuals against RSV. This virus is a common cause of respiratory tract infections, particularly known for leading to lower respiratory tract diseases such as bronchiolitis and pneumonia. These are serious lung diseases, especially in older adults, infants, and those with weakened immune systems.

Abrysvo and Arexvy are typically used in older adults to prevent RSV infections. The Centers for Disease Control and Prevention (CDC) recommends that adults 60 years and older receive a single dose in late summer or early fall. 

Abrysvo stands out as it is also approved for use in pregnant women between 32 and 36 weeks of pregnancy. Administering Abrysvo to pregnant women can help protect babies from severe lung diseases from birth until they are six months of age. A single dose of Abrysvo during pregnancy is recommended anytime between September and January. Arexvy is not approved for pregnant individuals.

 

Abrysvo vs. Arexvy: Compare conditions treated
Condition Abrysvo Arexvy
Active immunization to prevent RSV-induced lower respiratory tract disease in adults 60 years and older Yes Yes
Active immunization in pregnant women to prevent RSV-induced lower respiratory tract disease in infants from birth to 6 months Yes No

 

Is Arexvy better than Abrysvo?

Abrysvo and Arexvy are both effective and approved for preventing RSV-related lung diseases. The better option may depend on the intended purpose and cost-effectiveness. No head-to-head clinical studies have been carried out to compare Arexvy to Abrysvo. However, clinical trials have tested these vaccines against placebos.

In a Phase 3 clinical trial for Abrysvo, funded by Pfizer Inc., findings showed that it had a 67% efficacy in preventing RSV infections with at least two symptoms among individuals ages 60 and older. Moreover, the vaccine demonstrated an 86% effectiveness in protecting against more severe RSV illness characterized by three associated symptoms.

In a Phase 3 trial for Arexvy, funded by GSK, a single dose showed strong protection against severe lung infections caused by RSV. The vaccine was around 83% effective in preventing serious infections and 72% effective in preventing acute RSV-associated infections. Although the vaccine caused more temporary side effects than a placebo, it was generally safe and effective in preventing severe lung infections in older adults. Another study in pregnant women found that Arexvy reduced the risk of severe respiratory disease in newborns by 69%.

Consult a healthcare provider for guidance on the most appropriate RSV vaccine for your situation. 

Abrysvo vs. Arexvy: Insurance coverage and cost comparison

Insurance companies may cover both vaccines, and they are typically eligible for coverage under Medicare Part D. This means that most individuals with Medicare can receive the vaccine with little to no out-of-pocket cost.

The actual cost of these vaccines without insurance can vary, but tools like SingleCare can help manage those expenses. SingleCare offers cost-saving coupons that could help with managing the expenses of these vaccines, but specific prices might change over time and could also vary depending on the location and provider.

 

Compare costs & coverage of Abrysvo vs. Arexvy
Abrysvo Arexvy
Typically covered by insurance? Yes Yes
Typically covered by Medicare Part D? Yes Yes
Quantity 1, 120 mcg/0.5 ml intramuscular solution 1, 120 mcg/0.5 ml intramuscular solution
SingleCare cost $300 $285

 

Abrysvo vs. Arexvy side effects

Both vaccines share similar common side effects, which are typically mild and resolve on their own. 

One of the most frequently reported side effects associated with both Abrysvo and Arexvy is pain at the injection site, which is a common occurrence with many types of injections. Some people may feel soreness or discomfort in the area where the vaccine was administered. 

Some individuals who received these vaccines have also reported feeling tired or experiencing muscle pain. In addition, some recipients report having a headache after the vaccination. Unlike Arexvy, Abrysvo has also been reported to cause nausea and diarrhea.

While these side effects are generally not serious, both vaccines can potentially cause more severe adverse reactions. An example of a serious side effect could include an allergic reaction, though this is rare.

RELATED: Arexvy side effects and how to avoid them

 

Compare side effects of Abrysvo vs. Arexvy
Abrysvo Arexvy
Side Effect Applicable? Frequency Applicable? Frequency
Injection site pain Yes 40% Yes 61%
Fatigue Yes 16% Yes 34%
Muscle pain Yes 27% Yes 29%
Headache Yes 31% Yes 27%
Joint pain Yes 8% Yes 18%
Nausea Yes 20% No –
Diarrhea Yes 6% No –
Source: DailyMed (Abrysvo), DailyMed (Arexvy)

Abrysvo and Arexvy drug interactions

The Abrysvo and Arexvy FDA labels of these vaccines don’t list any reported drug interactions. Therefore, the risk of interacting with most prescription medications, over-the-counter medicines, and herbal supplements is low. At this time, however, specifics on drug interactions are not broadly available.

Taking immunosuppressant drugs can potentially reduce the effectiveness of the Abrysvo and Arexvy vaccines since these medications weaken the immune system’s response. Consult a healthcare provider for personalized guidance on getting either vaccination if you are taking any medications.

 

Immunosuppressant drugs that may interact with Abrysvo and Arexvy
Drug Drug Class Abrysvo Arexvy
Neoral (Cyclosporine) 

Prograf (Tacrolimus)

 Calcineurin inhibitors Yes Yes
Rapamune (Sirolimus) 

Zortress (Everolimus)

 mTOR Inhibitors Yes Yes
CellCept (Mycophenolate mofetil) 

Bredinin (Mizoribine)

 Antimetabolites Yes Yes
Arava (Leflunomide) 

Imuran (Azathioprine)

 Disease-modifying Antirheumatic Drugs (DMARDs) Yes Yes
Consult a healthcare professional for other possible drug interactions.

Abrysvo and Arexvy drug warnings

Abrysvo carries a risk of premature birth in pregnant women. Studies show that people who took Abrysvo had more preterm births compared to those who took a placebo. Because of this, it is recommended that Abrysvo should only be given to pregnant women between 32 and 36 weeks of pregnancy. Researchers are still studying whether Abrysvo directly causes these early births. 

Both Abrysvo and Arexvy can cause severe allergic reactions, including anaphylaxis, which is a life-threatening allergic response that can occur quickly. It is important to be monitored by a healthcare provider after getting the vaccine to ensure immediate medical attention if a reaction occurs. 

Additionally, people might faint after getting these injections. Therefore, measures should be taken to prevent any injuries if fainting occurs following the vaccination.

For individuals with weakened immune systems, such as those undergoing treatment that suppresses the immune system, the response to Abrysvo and Arexvy might not be as potent. This means the body might not react to the vaccine as effectively as expected.