The World Health Organization (WHO) no longer considers COVID-19 a public health emergency. In the United States, data from the Centers for Disease Control and Prevention (CDC) show that although COVID-19 infections aren’t spreading widely across the whole country, some states are seeing more cases. Local outbreaks can still happen, and the virus remains a concern, especially for people with weakened immune systems like those with myasthenia gravis (MG).

MG is a chronic autoimmune neuromuscular disease that causes muscle weakness. An autoimmune disease happens when the immune system mistakenly attacks the body’s own healthy cells. If you have an autoimmune disease, like myasthenia gravis, you may be at higher risk for severe COVID-19. Keep reading to learn how MG can make COVID-19 more serious, how COVID-19 can worsen MG symptoms, and how you can protect yourself.

1. People with MG Have an Increased Risk of Developing Severe COVID-19 Symptoms

If you have MG, you may have a higher risk of developing severe COVID-19 symptoms that require more advanced treatments, such as hospitalization, intensive care unit (ICU) care, or needing a ventilator to help you breathe. It’s important to note that most of these studies were conducted before widespread vaccination. While some studies showed an increased risk, others did not.

Two studies show that having MG could increase the risk of severe COVID-19 symptoms. A 2022 study in the U.S. found that people with MG were more likely to be admitted to the hospital or need care in the ICU than people without MG.

Researchers from another 2023 study in Canada had similar findings. In this study, they compared the outcomes of people in the general population (without MG), people with MG, and people with another autoimmune disease, rheumatoid arthritis (RA). When compared to both the general population and people with RA, people with MG had an increased risk of being hospitalized or dying from COVID-19.

Not all studies show that people with MG have worse COVID-19 outcomes. For example, researchers at one neurology clinic found that people with MG at their clinic didn’t experience more severe cases of COVID-19. However, this was a small study with only 141 people with MG, so its findings may not apply to everyone. More research is ongoing to better understand the complex relationship between COVID-19 and MG and how to best protect people with MG.

2. People With MG Are More Likely To Have Other Medical Conditions Associated With Severe COVID-19

MG isn’t listed by the CDC as a medical condition associated with severe COVID-19. However, people with MG may be more likely than the general population to develop more medical conditions (comorbidities) linked with severe COVID-19, including:

• Heart disease
• Diabetes (high blood sugar)
• Respiratory (breathing) disorders

3. People With More Severe MG Symptoms May Have an Increased Risk of Severe COVID-19 Symptoms

MG is a neuromuscular disorder that causes muscle weakness. When muscle weakness affects certain parts of the body, there may be an increased risk of developing severe COVID-19 symptoms.

In MG, the immune system attacks the space where nerves and muscles meet, called the neuromuscular junction. This makes it difficult for the muscles and nerves to communicate, resulting in muscle weakness. At first, MG may only affect the muscles of the eye (called ocular MG). However, about 80 percent of people with ocular MG eventually develop muscle weakness in other parts of the body (known as generalized myasthenia gravis).

People with generalized MG are more likely to have severe COVID-19 symptoms compared to people with ocular MG. In generalized MG, symptoms like dysphagia (difficulty swallowing) and difficulty breathing increase the risk of severe symptoms and death in COVID-19.

4. A COVID-19 Infection May Trigger an MG Flare

An MG flare (also called an MG exacerbation) is when muscle weakness from MG worsens.

In general, viral infections, including COVID-19 tend to worsen autoimmune conditions, like MG. People with severe COVID-19 symptoms may be more likely to have an MG exacerbation. Also, people with generalized MG may have a higher chance of MG flares with COVID-19 than those with ocular MG.

An MG flare-up may be more likely in the first week after developing severe COVID-19 symptoms. In one study, MG flare symptoms mostly affected the eyes, causing issues like double vision. However, other symptoms of an MG flare can also develop, such as muscle weakness in the:

• Arms and legs
• Neck
• Respiratory muscles (leading to breathing difficulty)

If muscle weakness affects the respiratory muscles, it can lead to a myasthenic crisis and respiratory failure. In a myasthenic crisis, the respiratory muscles become so weak it’s impossible to move enough air in and out of the lungs. If this happens, a ventilator is usually needed to get enough oxygen into the blood. This could be why researchers have found an increased risk of people with MG needing a ventilator with COVID-19.

MG flares have also been linked to experimental treatments for COVID-19, including azithromycin (Zithromax) and hydroxychloroquine (Plaquenil, Sovuna). These medications may worsen MG symptoms in some people and should be used with caution in those with MG.

5. Immunosuppressive Therapy Doesn’t Increase the Risk of Severe COVID-19

Many people with MG take medications called acetylcholinesterase inhibitors, such as pyridostigmine (Mestinon, Regonol). These medications help nerves communicate with muscles to improve movement and strength. But if they don’t work well enough, doctors may prescribe immunosuppressive therapy to better control the disease. Examples of immunosuppressive therapy for MG include:

• Azathioprine (Azasan, Imuran)
• Corticosteroids, such as prednisone
• Cyclosporine (Gengraf, Neoral)
• Intravenous immunoglobulin (IVIG) (Alyglo, Asceniv, Bivigam, Carimune)
• Mycophenolate mofetil (CellCept, Myfortic, Myhibbin)
• Rituximab (Riabni, Rituxan, Ruxience, Truxima)

According to the CDC, people who have been taking immunosuppressants for a long time have an increased risk of developing severe COVID-19 symptoms. However, more recent studies have shown this may not be true for people with MG. A 2024 study found that people with MG taking medication that suppressed the immune system didn’t have an increased risk of catching COVID-19 or the risk of severe symptoms. In fact, stopping immunosuppressive therapy may increase the risk of a relapse or MG flare.

Medication Changes During a COVID-19 Infection

Your healthcare team will work with you to determine the best course of treatment for your MG during a COVID-19 infection. Do not stop taking any of your MG medications without first talking to your doctor.

In some cases, immunosuppressive drugs for MG may also help prevent serious complications of COVID-19. Cytokine release syndrome (also called a cytokine storm) is a life-threatening complication of COVID-19 that happens when the immune response to the COVID-19 virus is too strong. Immunosuppressants, such as IVIG, prednisone, and tocilizumab (Actemra, Tofidence, Tyenne) may help treat or prevent a cytokine storm.

Some doctors worry that drugs like rituximab could make COVID-19 more severe. Rituximab works by targeting B cells — a type of white blood cell that helps to make antibodies that recognize and attack foreign invaders, such as viruses. Several studies in people with multiple sclerosis show that taking B-cell-directed treatments increases the risk of severe COVID-19 symptoms.

Your healthcare team can help you understand the risks and benefits of changing your MG treatment during a COVID-19 infection.

6. A COVID-19 Vaccine Can Prevent Severe COVID-19 Symptoms in People With MG

In clinical trials, people with MG who’ve had a COVID-19 vaccination had milder symptoms compared to those who didn’t get the vaccine. A 2024 study found that people with MG who had been vaccinated had a lower risk of hospitalization, ICU admission, and ventilator use compared to people who hadn’t been vaccinated. Another study also found that most of the people who died after a COVID-19 infection weren’t vaccinated.

Several studies have confirmed that COVID-19 vaccines are safe for people with MG. When the first round of COVID-19 vaccines was released, a 2023 study in Canada found that many people with MG received the vaccine. Researchers found that hospitalizations in people with MG didn’t increase in the 30 days after they got the vaccine. This suggests that the vaccine didn’t worsen MG in people who got it. Another 2023 study in Israel found that the Pfizer vaccine wasn’t associated with an increased risk of developing or worsening MG.

Researchers are still tracking the relationship between COVID-19 and MG. There have been case reports of new-onset MG in people who have had a COVID-19 vaccine or the infection. More research is needed to find out if the vaccine or infection directly causes MG.

It’s important to stay up to date with all of your vaccinations, including COVID-19. Talk to your neurologist to find out if you’re eligible for COVID-19 vaccinations including boosters, to make sure you have the best possible protection.

7. If You Get COVID-19, Watch for Severe Symptoms

Even if you take precautions, you may still get COVID-19. If this happens, you should monitor yourself for any symptoms of severe COVID-19 or an MG flare or crisis. Seek immediate medical care if you experience any of the following symptoms:

• Shortness of breath or difficulty breathing
• Chest pain that doesn’t go away
• Confusion
• Inability to stay awake
• Blue or pale-colored skin, especially on the lips or nail beds
• Difficulty swallowing
• Worsening muscle weakness

Connect With Others Who Understand

On MGteam, the social network for people with myasthenia gravis and their loved ones, more than 2,800 members come together to ask questions, give advice, and share their stories with others who understand life with myasthenia gravis.

Have you had COVID-19? Did you get a COVID-19 vaccination? Share your thoughts in the comments below, or start a conversation by posting on MGteam.