Vaccination against COVID-19 using inactivated viruses may be safe in patients with stable myasthenia gravis (MG), according to the results of a new study published in the journal Neurological Sciences. However, patients with generalized disease “may be more likely to develop increased muscle weakness after vaccination,” the authors of the study said. 

There has been concern that vaccination against COVID-19 may trigger or worsen autoimmune diseases such as MG.

Here, a team of researchers from China analyzed 106 MG patients in order to determine the impacts of COVID-19 vaccination on the severity of disease symptoms.

Read more about the symptoms of MG

Of these 106 patients, 28 were men and 68 were women. The median age of the patients was 41 years. Half of the patients had generalized MG and 69.8% were positive for acetylcholine receptor antibody. Around a fifth of the patients had accompanying thymoma.

Before the vaccination, the symptoms of muscle weakness were stable in almost all patients (102 patients out of 106).

Following vaccination muscle weakness worsened in 9.4% of the patients. Most of these patients reported, “slight symptom worsening that resolved quickly.” A total of 2 patients had serious symptom-worsening and required hospitalization.

“Adverse events leading to aggravation of MG require further study,” the study authors concluded. “Additional clinical studies are needed to determine the prevalence of such adverse outcomes.”

MG is a rare autoimmune disease affecting the neuromuscular junction. During the disease, autoantibodies are made that mistakenly attack and injure receptors found on muscles that receive nerve impulses. This leads to progressive muscle weakness.

The exact cause of the disease is not known but in some cases, it is known to develop after an infection, after surgery, or after the administration of certain drugs. Some people may have a genetic predisposition to the development of MG.


Wang HY, Qiu L, Ou CY, et al. An observational study on the safety of COVID-19 vaccination in patients with myasthenia gravis. Neurol Sci. Published online May 9, 2023. doi:10.1007/s10072-023-06811-y