Avindra Nath, MD, responds:
Yes, you can get a flu shot and you should. Otherwise, you run the risk of coming down with the flu, which could be deadly if you retain secretions in your lungs and develop pneumonia. And if you're bedridden due to illness, you could develop ulcers and urinary tract infections.
In short, the risk of complications from flu is usually greater than the risk that the vaccine might exacerbate neurologic symptoms. (For example, someone with multiple sclerosis who develops a fever from a vaccine could experience a flare-up. But once the fever is under control, the symptoms should abate.) Even if the vaccine is only partially effective, which happens sometimes, and you do get the flu, the symptoms probably won't be as severe as they might have been if you hadn't been vaccinated.
Outdated Thinking
Up until 11 years ago, some researchers thought the flu vaccine might trigger an immune response that could lead to a neuroimmune disorder. Those concerns were put to rest by a 2004 review from a panel of experts at the Institute of Medicine, an independent non-profit that provides unbiased and authoritative advice to policymakers and the public.
The experts looked at research studies to determine whether influenza vaccines increase the risk of developing neurologic conditions such as multiple sclerosis, Guillain-Barre syndrome, and optic neuritis, and concluded that vaccines did not raise the risk. The review committee did recommend additional research to better understand how influenza develops and to anticipate which strains might be more neurologically active.
A Compromised Immune System
In a 2014 study in the journal Vaccine, a team of researchers in Italy reported on vaccination recommendations for patients with neuromuscular diseases. They looked at the impact of the flu vaccine in people with neuromuscular diseases who had normal immune systems and those whose immune systems were compromised by an underlying disease or who were taking steroids.
For those who had a neuromuscular disease and a normal immune system, the safety and efficacy of the vaccine were the same as they are for the general population. In those with a compromised immune system, the vaccine did not always "take" as well. For those patients, the authors recommend getting an inactivated vaccine, which is commonly given as a nasal spray, instead of the live attenuated vaccine.
Read more about vaccine guidelines for people with multiple sclerosis.
Dr. Nath is the clinical director of the National Institute of Neurological Disorders and Stroke (NINDS) at the National Institutes of Health (NIH), president of the International Society of Neurovirology, and a member of the American Academy of Neurology.
