New RSV shots tied to rare nervous system disorder — should you worry?

The new RSV vaccines approved for older adults may be linked to a slightly increased risk of a rare neurological condition, a recent analysis finds. 

However, the Centers for Disease Control and Prevention (CDC) says the benefits of the vaccines outweigh this slight increased risk. Therefore, the agency still recommends that adults 60 years and older get an RSV vaccine in consultation with their doctor. The available vaccines include one called Arexvy and another called Abrysvo.

The recent research — published May 30 by CDC scientists in the agency's Morbidity and Mortality Weekly Report — is consistent with findings in the clinical trials for the vaccines, according to study leader Anne Hause, an epidemiologist and program lead for V-safe in the CDC's Immunization Safety Office. During clinical trials, researchers observed higher-than-expected rates of Guillain-Barré syndrome, a disorder in which the immune system attacks Healthy nerves. 

While Guillain-Barré syndrome was noted as a potential concern during the trials, the trials were too small to tease out any possible connection to the shots. Real-world monitoring data involves much larger groups of patients and thus helps confirm the link that trial data hinted at.

Related: Who should get the new RSV vaccines? Here's everything you need to know

Guillain-Barré syndrome causes tingling, numbness and muscle weakness, and it can progress to paralysis. According to the Mayo Clinic, most people recover completely from this illness, but it can take months or years. In severe cases, the condition can affect the muscles that support breathing and be life-threatening.

While Guillain-Barré is fairly rare, RSV, or respiratory syncytial virus, circulates every year and poses a threat to children and older adults, in particular. Among U.S. adults over 65, the seasonal infection kills approximately 6,000 to 10,000 people each year, according to the CDC.