Cases of influenza are more frequent during the late fall and winter months. A common question is whether people with multiple sclerosis should choose to be vaccinated against influenza (flu). The following summary of current facts about the influenza vaccination and MS should be of assistance:

Can the influenza vaccination trigger an MS attack?
The most common side effect from any vaccination is soreness at the injection site. In addition, any vaccination can cause other side effects including short-term fever (one to two days) in some cases. With flu, fever is usually seen in individuals who have had no previous exposure to the influenza virus, e.g., young children.

A study in 1997 by Dr. Aaron Miller, Maimonides Medical Center, Brooklyn, NY, looked directly at any possible link between the influenza vaccination and MS attacks. He found that people with relapsing-remitting MS, who had the flu vaccine, did not have more relapses then those who received a placebo injection.

"This study clearly supports the view that influenza vaccination is not associated with a statistically significant increase in MS attacks or worsening. People with MS should discuss the issue with their own physicians when making a decision about the flu vaccine," noted Dr. William J. McIlroy, national medical advisor, Multiple Sclerosis Society of Canada.

In general, who should not receive the influenza vaccination?
The influenza vaccination (flu shot) is considered safe for most individuals including women who are pregnant and women who are breastfeeding.

The following should not receive the flu vaccine:

• Infants under the age of six months;
• Anyone who is allergic to or has had an anaphylactic hypersensitivity to eggs or egg products;
• Anyone who has had an allergic or anaphylactic reaction to a previous flu vaccination;
• Anyone who is actively unwell at the time of the vaccination (high fever, chills, etc.) should postpone receiving the flu vaccine until symptoms have become better;
• Anyone with an active or unstable neurological condition – this includes people with MS who are having an MS attack or relapse.

My MS is stable right now. Should I get the flu shot?
The study by Dr. Miller strongly suggests that people with MS who are not currently having MS attacks or relapses can benefit from having the flu shot. Influenza is a serious illness bringing high fever, headache, muscle aches, coughing, and extreme fatigue. Recovery from the flu is usually seven to 10 days, but in some cases even longer.

My local public flu clinic won't give me the vaccination because I have MS. Why not?
Flu clinics are designed to deliver the vaccine to the greatest number of people in the shortest amount of time. Clinic personnel do not have time to take detailed medical histories from individuals. Additionally, they have no particular expertise in multiple sclerosis and probably would not be able to tell whether someone is having an MS relapse. Some public flu clinics will not provide the flu shot to individuals with MS or other neurological conditions and will advise them to see their own doctors to discuss receiving the vaccination.

ASK MS Information System Code: 2.7.2.8.w

Disclaimer
The Multiple Sclerosis Society of Canada is an independent, voluntary health agency and does not approve, endorse or recommend any specific product or therapy but provides information to assist individuals in making their own decisions.