Bexsero is a brand-name intramuscular injection prescribed to help prevent meningitis B in some children and adults. As with other drugs, Bexsero can cause side effects, including injection site reactions, fatigue, and muscle pain.

Bexsero can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who received Bexsero in clinical trials:

* For more information about this side effect, see the “Side effect specifics” section below.

Mild side effects can occur with Bexsero. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Bexsero’s prescribing information.

Mild side effects that have been reported with Bexsero include:

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect after receiving Bexsero and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Side effect specifics” below.
† An allergic reaction is possible after receiving Bexsero. However, this side effect wasn’t reported in clinical trials. To learn more, see the “Side effect specifics” section below.

Bexsero may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Bexsero’s prescribing information.

If you develop serious side effects after receiving Bexsero, 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.

Serious side effects and their symptoms may include severe allergic reaction.

Note: An allergic reaction is possible after receiving Bexsero. However, this side effect wasn’t reported in clinical trials. To learn more, see the “Side effect specifics” section below.

Bexsero may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

How long do side effects of Bexsero typically last?

Side effects of Bexsero typically last only a few hours up to several days. However, there were reports of injection site reactions lasting a month or longer in the drug’s clinical trials. (Bexsero is a vaccine that’s given as an intramuscular injection.) For example, some people experienced hardening of the skin where the injection was given. For more information about this effect, see the “Side effect specifics” section below.

If you have questions about what to expect with Bexsero injections, talk with your doctor or pharmacist.

Can Bexsero cause long-term side effects?

It’s unlikely that Bexsero will cause long-term side effects. In clinical trials, there were no reports of long-term side effects in people who were given the vaccine. Most side effects of Bexsero, such as fatigue, are mild and temporary. To learn more about fatigue, see the “Side effect specifics” section below.

Talk with your doctor or pharmacist if you have questions about Bexsero and long-term side effects.

Learn more about some of the side effects that Bexsero may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Bexsero.

Fatigue

Fatigue was among the most common side effects reported in Bexsero clinical trials.

It’s common for vaccines to cause fatigue, according to the Centers for Disease Control and Prevention (CDC). A vaccine helps your immune system build immunity to a specific infectious illness.

Certain side effects of vaccines, such as fatigue, often mean your immune system is working. With Bexsero, your body is building immunity against meningitis B, a type of bacterial meningitis.

What you can do

If you experience fatigue after your Bexsero injection, keep in mind that it’s likely temporary. It may be helpful to get some extra sleep for a few days. Your doctor may suggest avoiding strenuous exercise and taking a few days off from your typical activities.

However, your doctor may also advise you to exercise your injected arm after you receive your shot. (Bexsero is given as an intramuscular injection, typically into the upper arm.) Moving your arm around may help reduce soreness.

If your fatigue lasts more than a few days after receiving Bexsero, talk with your doctor. They’ll evaluate your symptoms to help determine the cause of your fatigue.

Injection site reaction

In clinical trials, injection site reaction (symptoms of swelling, irritation, or pain) was the most common side effect after Bexsero injection. (Bexsero is given as an intramuscular injection.) Bexsero injection site reactions included skin discoloration and hardening or thickening of the skin.

Injection site reactions were typically mild and temporary in the drug’s clinical trials. However, there were reports of symptoms lasting a month or longer.

What you can do

Your doctor may recommend getting the injection in your nondominant arm. They may also give you some self-care tips to help ease your symptoms. For example, a cool washcloth or ice pack on the injection site may help lessen the pain and swelling. Your doctor may also recommend exercising the affected arm as much as possible.

With your doctor’s approval, taking a pain reliever such as Tylenol (acetaminophen) may increase your comfort level. Talk with your doctor if any injection site symptoms persist.

Allergic reaction

As with most drugs, Bexsero can cause an allergic reaction in some people. This side effect wasn’t reported during the drug’s clinical trials. However, there were some reports of allergic reaction after the drug was approved.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms. They’ll also determine whether you should receive your second Bexsero dose.* However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* Doctors typically recommend two doses of Bexsero spaced at least 1 month apart. To learn more about Bexsero’s recommended dosage, see this article.

Be sure to talk with your doctor about your health history before you receive Bexsero. This drug is a vaccine that helps prevent meningitis B, a type of bacterial meningitis. Bexsero may not be suitable for you if you have certain medical conditions or other factors that affect your health. These are considered drug-condition or drug-factor interactions.

With Bexsero, the conditions and factors to consider include:

Weakened immune system. Bexsero may be less effective in people with a weakened immune system. Conditions that can weaken your immune system include an active infection and cancer. If you have an infection, your doctor may recommend delaying Bexsero until your infection clears. For other conditions, talk with your doctor about whether you can receive Bexsero.

Allergic reaction. If you’ve ever had an allergic reaction to Bexsero or any of its ingredients, your doctor will likely recommend that you do not receive Bexsero. Your doctor may be able to recommend a different vaccine for you.

Latex allergy. If you have an allergy to latex, you may experience an allergic reaction to Bexsero. The tip cap of Bexsero prefilled syringes contain latex. Be sure to tell your doctor if you have a latex allergy. Your doctor may be able to recommend a different vaccine for you.

Pregnancy or breastfeeding. If you’re pregnant or breastfeeding your child, Bexsero may not be safe for you or your child. Talk with your doctor before receiving Bexsero.

Alcohol consumption. If you drink alcohol, it’s likely safe to consume before and after receiving your Bexsero vaccine. If you have questions about how much alcohol is safe to drink before and after a Bexsero injection, talk with your pharmacist or doctor.

If you’d like to learn more about Bexsero, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from the drug.

Besides talking with your doctor, you can do some research on your own. These articles might help:

Disclaimer: Medical News Today 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.