Health officials are investigating if there is a link between two new RSV vaccines and Guillain-Barre syndrome.

Last year, an advisory panel for the Centers for Disease Control and Prevention (CDC) recommended Americans aged 60 and older have the option of a single dose of RSV vaccine.

Two RSV vaccine options would become available, one by Pfizer and the other by GSK.

The CDC said patients should talk to their doctor before taking the shot.

“Serious neurologic conditions, including Guillain-Barre syndrome (GBS), have been reported after RSV vaccination in clinical trials of older adults. It is unclear whether the vaccine caused these events,” the CDC writes.

The Associated Press reports that officials are investigating more than 20 cases of Guillain-Barre syndrome.

From the Associated Press:

Officials said they were investigating more than 20 cases of Guillain-Barre syndrome, an rare illness in which a person’s immune system damages nerve cells, causing muscle weakness and paralysis. An estimated 3,000 to 6,000 people develop GBS in the U.S. each year, and it’s more commonly seen in older people, according to the CDC.

Most people fully recover from the syndrome, but some have permanent nerve damage. Guillain-Barre can occur in people after they are infected with a virus, but in some instances cases have been linked to vaccinations.

RSV, or respiratory syncytial virus, is a common cause of cold-like symptoms but it can be dangerous for infants and the elderly.

Last year, the CDC signed off on a recommendation made by the advisory panel, aimed at Americans age 60 and older. It was for a single dose of RSV vaccine. There were two options, one made by Pfizer and the other by GSK.

“Two people who received Pfizer’s respiratory syncytial virus (RSV) vaccine during a clinical trial were later diagnosed with Guillain-Barre syndrome, and the US Food and Drug Administration has asked Pfizer to conduct a safety study if the shot is approved, according to agency documents released Friday,” CNN reports.

The Pharma giant claims its RSV vaccine, Abrysvo, protects older adults from respiratory syncytial virus for more than two seasons.

Pfizer said one dose of Abrysvo was 77.8 percent effective against lower respiratory tract disease associated with RSV following the second season.

Out of 20,000 vaccine recipients in Pfizer’s Phase 3 clinical trial, two Guillain-Barre syndrome cases were confirmed in adults in their 60s.

Per CNN:

One person’s illness had completely resolved after three months, and another was improving after six months. There were no Guillain-Barre cases among people who didn’t receive the shot.

“Given the temporal association and biological plausibility, FDA agrees with the assessments of the investigators that these events were possibly related to study vaccine. … Therefore, [Guillain-Barre] is being considered an important potential risk,” the FDA says in the documents, which were released ahead of a meeting of its independent vaccine advisers, the Vaccines and Related Biological Products Advisory Committee, on Tuesday and Wednesday.

The committee is scheduled to discuss and make recommendations on RSV vaccines for adults 60 and older from Pfizer and GSK.

Guillain-Barre syndrome is a rare neurological disorder in which the immune system attacks its own nerves, causing muscle weakness and sometimes paralysis. Although most people recover completely, some cases can be fatal or have lasting effects.

The incidence of Guillain-Barre is about 1.5 to 3 cases for 100,000 adults over age 60 in the US annually, according to the FDA.

“Given the higher than background rate of GBS observed in the Phase 3 study, FDA will recommend a postmarketing study and enhanced surveillance for further evaluation of GBS and other immune-mediated demyelinating conditions with postmarketing use,” the FDA says.

In a briefing document submitted for next week’s meetings, Pfizer says that the cases have other possible explanations and that its shot is a “well-tolerated and safe vaccine, with a benefit-to-risk ratio that is favorable.” The company says it will conduct a safety study on Guillain-Barre syndrome if its RSV shot is approved.

Join The Conversation. Leave a Comment.


We have no tolerance for comments containing violence, racism, profanity, vulgarity, doxing, or discourteous behavior. If a comment is spam, instead of replying to it please click the ∨ icon below and to the right of that comment. Thank you for partnering with us to maintain fruitful conversation.