Arexvy is a vaccine that’s used to prevent lower respiratory tract infections caused by the respiratory syncytial virus. Arexvy can cause side effects that range from mild to serious. Examples include fatigue and muscle aches.

Arexvy is a respiratory syncytial virus (RSV) vaccine used in adults ages 60 years and older to prevent lower respiratory tract infections. It comes in a suspension that a healthcare professional will inject into your upper arm muscle.

Keep reading to learn about the common, mild, and serious side effects that Arexvy can cause. For a general overview of the vaccine, including details about its uses, see this article.

Some people may experience mild to serious side effects after receiving Arexvy. Examples of the vaccine’s commonly reported side effects include:

  • injection site reactions*
  • joint pain
  • fatigue (low energy)
  • muscle aches
  • headache

* To learn more about this side effect, see the “Side effects explained” section below.

Mild side effects have been reported with Arexvy. These include:

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist.

Arexvy may cause mild side effects other than those listed above. See the vaccine’s prescribing information for details.

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after receiving Arexvy, but this side effect wasn’t reported in studies.

Serious side effects have been reported with Arexvy. These include:

If you develop serious side effects after receiving Arexvy, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after receiving Arexvy, but this side effect wasn’t reported in studies.

Note: After the Food and Drug Administration (FDA) approves a vaccine, both the FDA and the Centers for Disease Control and Prevention (CDC) track its side effects. If you’d like to report a side effect you’ve had with Arexvy, visit the Vaccine Adverse Event Reporting System (VAERS) website.

Get answers to some frequently asked questions about Arexvy’s side effects.

How do side effects of Arexvy compare with those seen with Abrysvo?

Arexvy and Abrysvo are both RSV vaccines approved for use in adults ages 60 years and older. However, only Abrysvo is approved for use during pregnancy to prevent RSV in newborns.

Because they are both RSV vaccines, their side effects are similar. But pregnant people may experience nausea and vomiting with Abrysvo.

If you have questions about side effects of Arexvy or Abrysvo, talk with your doctor.

Does Arexvy cause long-term side effects?

It’s possible. Long-term side effects include those that may start at any time after you receive a vaccine. They also include side effects that may not go away, even weeks after you receive a vaccine.

Long-term side effects with Arexvy are very rare. Examples of long-term side effects reported in Arexvy’s studies include:

If you’re concerned about possible long-term side effects from Arexvy, talk with your doctor or pharmacist.

Learn more about some of the side effects Arexvy may cause.

Irregular heartbeat

Irregular heartbeat (atrial fibrillation) was an uncommon side effect reported in studies of Arexvy. Irregular heartbeat may cause symptoms such as:

  • racing or pounding heartbeat
  • fainting
  • fatigue (low energy)
  • sweating
  • shortness of breath
  • chest pain
  • dizziness
  • weakness
  • lightheadedness

Factors that can increase the risk of irregular heartbeat when receiving this vaccine include:

  • history of heart problems
  • dehydration
  • smoking
  • excess caffeine intake

What might help

To decrease your risk of irregular heartbeat, stay hydrated and reduce your caffeine and nicotine use, if applicable.

If you have an irregular heartbeat after receiving Arexvy, talk with your doctor right away. They’ll likely recommend that you seek medical care soon. If you develop severe shortness of breath or chest pain, call 911 or go to the nearest emergency room immediately, as these symptoms could indicate a heart attack.

Injection site reactions

Injection site reactions were common side effects reported in studies of Arexvy. Injection site reactions may cause symptoms such as:

  • fever for 24 hours or less
  • darkened or discolored skin
  • a hard lump that may last for up to 30 days
  • pain
  • swelling

Factors that can increase the risk of injection site reactions when receiving this vaccine include:

  • history of sensitivity to vaccine ingredients
  • incorrect arm position

What might help

To help lower your chance of injection site reactions from Arexvy:

  • remove your entire arm from your shirt sleeve before the injection
  • inform your healthcare professional about previous vaccine sensitivities
  • relax and hang your arm down by your side
  • avoid hard rubbing of the injection area after you receive the injection

Vaccines work by causing a response from your immune system. So, a reaction at the injection site can still occur even if you don’t have vaccine sensitivities and your arm is positioned correctly. Most injection site reactions will clear up within 24–72 hours.

To help relieve your symptoms, you can take over-the-counter (OTC) medications, such as acetaminophen, for pain and move your arm regularly to increase circulation. Applying a cold compress to the area may also help with symptom relief. Be sure to talk with your doctor or pharmacist before taking any OTC medications.

Check with your doctor or pharmacist if you develop severe symptoms lasting longer than 24 hours, such as:

  • a swollen lymph node under your injection arm
  • a fever
  • discolored streaks from the injection site
  • difficulty lifting or moving your injection arm

Allergic reaction

Like most vaccines, Arexvy can cause an allergic reaction in some people. But this side effect wasn’t reported in studies.

Symptoms can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin (usually in your eyelids, lips, hands, or feet)
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

  • an antihistamine you swallow, such as Benadryl (diphenhydramine)
  • a product you apply to your skin, such as hydrocortisone cream

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

Keeping track of side effects

After you receive Arexvy, consider taking notes on any side effects you have. You can then share this information with your doctor.

Your side effect notes can include things such as:

  • how soon you had the side effect after receiving Arexvy
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Arexvy affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before receiving Arexvy.

Warnings

Arexvy can sometimes cause harmful effects in people who have certain conditions. This is known as a vaccine-condition interaction. Other factors may also affect whether Arexvy is a good treatment option for you.

Talk with your doctor about your health history before you receive Arexvy. Be sure to tell them if any of the following factors apply to you:

  • history of fainting with injections
  • weakened immune system
  • use of any prescription medications, OTC drugs, supplements, herbs, or vitamins
  • history of severe allergic reaction to any ingredient in Arexvy
  • previous allergic reaction to Arexvy
  • pregnancy
  • breastfeeding

Alcohol and Arexvy

There are no known interactions between alcohol and Arexvy. If you have questions about consuming alcohol after receiving Arexvy, talk with your doctor or pharmacist.

Pregnancy and breastfeeding with Arexvy

Before receiving Arexvy, it’s essential to talk with your doctor if you’re pregnant, breastfeeding, or planning to become pregnant or to breastfeed.

Arexvy has not been studied in people who are pregnant or breastfeeding and is approved only for people ages 60 years and older. However, if you are pregnant, talk with your doctor or pharmacist about Abrysvo, a CDC-recommended RSV vaccine for pregnant people.

Like most vaccines, Arexvy can cause a number of side effects that range from mild to serious. However, most are temporary and go away after a few days to weeks. If you have questions about side effects that Arexvy can cause, talk with your doctor.

Examples of questions to help get you started include:

To get information on different conditions and tips for improving your health, subscribe to any of Healthline’s newsletters. You may also want to check out the online communities at Bezzy. It’s a place where people with certain conditions can find support and connect with others.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.