Do you have questions about getting a COVID-19 vaccine?

If you are on treatment for multiple sclerosis (MS) and have questions about COVID-19 or the COVID-19 vaccines, contact your healthcare provider for answers and guidance. It is very important to continue taking your MS medicine as prescribed and to follow your healthcare provider’s treatment directions.

For additional information, there are helpful online resources that address the question of whether people with MS should get a COVID-19 vaccine, including the National MS Society and the The Consortium of Multiple Sclerosis Centers. To learn more about your vaccination options, talk with your healthcare provider.

US-REB-00324 04/2021

UNDERSTANDING REBIF® (interferon beta-1a)

The immune system and RMS

Relapsing multiple sclerosis (RMS) is an autoimmune disorder in which the body attacks itself. Specifically, the immune system attacks the coating (the myelin sheath) on the nerves in the brain, spinal cord, and eye area, which can cause scarring and prevent the nerves from communicating correctly. This communication breakdown can lead to symptoms of MS, which can vary in severity, and may lead to permanent damage.

In MS, immune cells mistakenly attack the neurons within the nervous system

Graphic showing the three kinds of immune cells that attack the neurons within the nervous system. Type 1 – Antigen presenting cells (APC); 2. T cells; and 3. B cells
Beta interferon icon

About beta interferons

Beta interferons are proteins your body produces naturally in response to viral infection. They regulate the activity of immune cells like APCs, T cells, and B cells.

Rebif®, a form of interferon beta, is nearly identical to the kind produced in the body. Rebif® has the same amino acid sequence (the same protein structure) as naturally produced beta interferon.




How Rebif® is thought to work

Rebif® is a form of interferon beta, an immunomodulator which helps to regulate the immune system. Rebif® is similar to the type of interferon beta produced naturally in your body. When you have RMS, treatment with an interferon therapy may reduce the activity of cells that are attacking your nervous system.


Graphic of circles inside circles with the three types of immune cells in the outermost circle and the beta interferon in the smallest middle circle to demonstrate how Rebif® is thought to work


The precise way in which Rebif® works in MS is not known. Talk to your healthcare provider to find out what Rebif® may mean for you and your RMS.

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Important Safety Information

Before beginning treatment, you should discuss the potential benefits and risks associated with Rebif with your healthcare provider.

Rebif can cause serious side effects. Tell your healthcare provider right away if you have any of the symptoms listed below while taking Rebif.

  • Behavioral health problems including depression and suicidal thoughts. You may have mood problems including depression (feeling hopeless or feeling bad about yourself), and thoughts of hurting yourself or suicide
  • Liver problems or worsening of liver problems including liver failure. Symptoms may include nausea, loss of appetite, tiredness, dark colored urine and pale stools, yellowing of your skin or the white part of your eye, bleeding more easily than normal, confusion, and sleepiness. During your treatment with Rebif you will need to see your healthcare provider regularly and have regular blood tests to check for side effects
  • Serious allergic and skin reactions. Symptoms may include itching, swelling of your face, eyes, lips, tongue or throat, trouble breathing, anxiousness, feeling faint, skin rash, hives, sores in your mouth, or skin blisters and peels
  • Injection site problems. Symptoms at the injection site may include redness, pain, swelling, color changes (blue or black), and drainage of fluid
  • Blood problems. Rebif can affect your bone marrow and cause low red and white blood cell and platelet counts. In some people, these blood cell counts may fall to dangerously low levels. If your blood cell counts become very low, you can get infections and problems with bleeding and bruising. Your healthcare provider may ask you to have regular blood tests to check for blood problems
  • Seizures. Some people have had seizures while taking Rebif

Rebif will not cure your MS but may decrease the number of flare-ups of the disease and slow the occurrence of some of the physical disability that is common in people with MS.

Do not take Rebif if you are allergic to interferon beta, human albumin, or any of the ingredients in Rebif.

Before you take Rebif, tell your healthcare provider if you have or have had any of the following conditions:

  • mental illness, including depression and suicidal behavior
  • liver problems, bleeding problems or blood clots, low blood cell counts, seizures (epilepsy), or thyroid problems
  • you drink alcohol
  • you are pregnant or plan to become pregnant. It is not known if Rebif will harm your unborn baby
  • you are breastfeeding or plan to breastfeed. Rebif may pass into your breastmilk. Talk with your healthcare provider about the best way to feed your baby if you take Rebif

Tell your healthcare provider about all medicines you take, including prescription and over-the-counter medicines, vitamins and herbal supplements.

The most common side effects of Rebif include:

  • flu-like symptoms. You may have flu-like symptoms when you first start taking Rebif. You may be able to manage these flu-like symptoms by taking over-the-counter pain and fever reducers. For many people, these symptoms lessen or go away over time. Symptoms may include muscle aches, fever, tiredness, and chills
  • stomach pain
  • change in liver blood tests

Tell your healthcare provider if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of Rebif. For more information, ask your healthcare provider or pharmacist.

Call your doctor for medical advice about side effects. 

You are encouraged to report negative side effects of prescription drugs to FDA. Visit, or call 1-800-FDA-1088.


Rebif® (interferon beta-1a) is a prescription medicine used to treat relapsing forms of multiple sclerosis, to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults.