Dealing With Multiple Sclerosis When You Have the Flu

Multiple sclerosis (MS) is an autoimmune condition that impacts the central nervous system—the brain and spinal cord—resulting in relapsing and remitting symptoms (a series of flares and remissions) that affect your vision, balance, and muscle coordination.

MS looks different in everyone.

It is important for people with MS to limit their flu risk because the flu has been shown to trigger or exacerbate (worsen) MS symptoms.

This article goes into detail about flu prevention, symptoms, and treatment for those with MS.

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MS Is a Risk Factor for the Flu

The link between infectious disease and MS, in particular, the two herpesviruses—Epstein-Barr virus (EBV) and human herpesvirus 6 (HHV-6)—have been suspected and researched for many years. However, the cause-and-effect association between MS and diseases has not been proven.

Certain viruses like influenza A and B do not seem to affect MS, but animal studies have revealed that the flu virus may increase the risk for relapse, which is a triggering of MS symptoms.

One study even found that the flu could double the risk of MS exacerbation.

More Studies Are Needed

Human studies are needed to make clear the association between flu and MS relapse.

Research scientists theorize that the immune system may go into overdrive to clear an upper respiratory viral infection like the flu. This activation of the immune system may also trigger MS symptoms.

While the association between MS and the flu is far from complete, studies show that there are more MS relapses in the winter months during flu season than at other times of the year, strengthening the argument for a potential association between the two. The possibility that flu affects MS symptoms underscores the importance of following flu prevention tactics and getting your seasonal flu vaccine.

Should MS Patients Get the Flu Shot?

The Centers for Disease Control and Prevention (CDC) recommends that all people with MS get a seasonal influenza vaccine. The CDC also recommends getting all other immunizations to prevent contagious diseases.

Talk with your healthcare provider if you are unsure of when you should be getting one or more vaccines. 

Reasons to Delay Flu Vaccination

Vaccination is highly recommended in those with MS, but there are a few reasons to delay vaccination. These include:

  • Avoiding live-attenuated vaccines: This is due to the theoretical risk of the virus triggering your MS symptoms. Live-attenuated vaccines induce immunity by introducing a weakened form of the virus, whereas inactivated vaccines contain no live virus, just genetic material that has been destroyed by heat, chemicals, or radiation that can still trigger an immune response.
  • Taking certain medications: Some medications, including corticosteroids, may impact your response to a vaccination. In this case, your healthcare provider may suggest delaying vaccinations while you make changes to your medication regimen. 

Discuss Hesitations With Your Healthcare Provider

It is natural to have questions about your health, especially when it comes to vaccination. Do not hesitate to reach out to your healthcare provider If you have any questions about the flu vaccine, its safety, or its effectiveness. Your healthcare provider will have the most up-to-date information.

Flu vs. MS Relapse Symptoms

Flu and MS symptoms are distinctly different, although nonspecific symptoms like fatigue and changes in your bowels may be present in both. The most common flu symptoms are:

  • Fever
  • Chills
  • Muscle aches (myalgia)
  • Cough
  • Sore throat
  • Head congestion
  • Headache
  • Nausea and vomiting
  • Diarrhea

If you are experiencing any of the above symptoms and any of the following symptoms, you may be having an MS relapse and should contact your healthcare provider:

  • Vision changes (blurred or double vision, pain in one or both eyes, or loss of vision indicative of optic neuritis)
  • Difficulty walking
  • Hearing loss
  • Speech problems
  • Muscle weakness
  • Numbness anywhere in the body
  • Spasticity
  • Pins, tingling, or a prickly feeling throughout the body 
  • Changes in sexual function
  • Bowel and bladder problems


Heat may trigger your MS symptoms. In fact, some people avoid hot tubs and certain exercises to decrease their risk of an MS exacerbation.

Fever has also been shown to increase your risk of MS relapse. Even a slight rise in body temperature can worsen your symptoms temporarily. Flares brought on by fever are known as pseudo-exacerbations because they are characterized by a temporary worsening of symptoms without causing actual inflammation or damage to myelin, the protective coating of nerves in the brain and spinal cord.

Flu Prevention 

The following tips may help you prevent getting sick from the flu: 

  • Avoid contact with anyone who may be sick with the flu.
  • Wash your hands regularly, using soap and water for at least 20 seconds or alcohol based hand sanitizer. 
  • Avoid touching your face with unclean hands.
  • If you work outside the home and are feeling sick, do not attend.
  • When sneezing, cover your mouth and nose or sneeze into your elbow.
  • Keep surfaces clean and sanitized.


The flu may exacerbate multiple sclerosis symptoms as a result of having a fever and a weakened immune system, underscoring the importance of flu prevention via proper hand hygiene and vaccination. 

A Word From Verywell 

If you have MS you may want to take extra precautions, especially during the winter months. Although there are many unknowns associated with flu and MS relapse, studies show that there are more MS relapses during flu season, underscoring the importance of following flu prevention advice and getting your seasonal flu vaccine to avoid serious medical complications.

Frequently Asked Questions

  • Does MS weaken the immune system?

    No. MS does not directly compromise the immune system although the drugs you take for it, like corticosteroids and disease-modifying therapies (DMTs), may.

  • How can MS patients boost their immune system?

    Sticking to a routine vaccination schedule and practicing proper hygiene like handwashing and not touching your face with unclean hands are good ways to prevent viral infections and boost your immune system. 

    Other general habits that increase your immune system include getting proper sleep (eight hours per day), never smoking, maintaining a healthy weight, exercising regularly, and eating a diet high in fruits, vegetables, and whole grains.

  • Do vitamin C and zinc supplements help MS flu risk?

    The antioxidants vitamin C and zinc play an important role in clearing free radicals in the body, but there are no well-documented or peer-reviewed studies of people with MS that show a clinical benefit related to antioxidant supplements. Therefore, the benefits of supplementation are more suggestive than definitive.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Steelman AJ. Infection as an environmental trigger of multiple sclerosis disease exacerbation. Front Immunol. 2015 Oct 19;6:520. doi:10.3389/fimmu.2015.00520

  2. Blackmore S, Hernandez J, Juda M, Ryder E, Freund GG, Johnson RW, Steelman AJ. Influenza infection triggers disease in a genetic model of experimental autoimmune encephalomyelitis. Proc Natl Acad Sci U S A. 2017 Jul 25;114(30):E6107-E6116. doi:10.1073/pnas.1620415114

  3. Virtanen JO, Jacobson S. Viruses and multiple sclerosis. CNS Neurol Disord Drug Targets. 2012;11(5):528-544. doi:10.2174/187152712801661220

  4. National Multiple Sclerosis Society. Vaccinations.

  5. Centers for Disease Control and Prevention. Flu symptoms and complications.

  6. Johns Hopkins Medicine. Relapse-remitting multiple sclerosis.

  7. Multiple Sclerosis Association of America. Multiple sclerosis relapses.

  8. Centers for Disease Control and Prevention. Healthy habits to prevent against the flu.

By Shamard Charles, MD, MPH
Shamard Charles, MD, MPH is a public health physician and journalist. He has held positions with major news networks like NBC reporting on health policy, public health initiatives, diversity in medicine, and new developments in health care research and medical treatments.