Health officials in the United States are currently investigating a potential connection between two newly developed vaccines for respiratory syncytial virus (RSV) and cases of a rare nervous system disorder in older adults. The investigation comes after a total of over 9.5 million vaccine recipients were reported, with fewer than two dozen cases of the nervous system disorder observed. Although the available information is limited, officials are treating these numbers as higher than expected and are actively gathering more data to determine if the vaccines caused the illnesses.

The investigation was presented at a meeting of an expert panel that advises the Centers for Disease Control and Prevention (CDC) on vaccines. According to officials, more than 20 cases of Guillain-Barre syndrome (GBS), a rare illness that causes muscle weakness and paralysis due to nerve cell damage, are currently under investigation. While estimates suggest that 3,000 to 6,000 people in the US develop GBS each year, the syndrome is more commonly seen amongst older individuals.

While most people fully recover from GBS, some experience permanent nerve damage. Guillain-Barre can occur after an individual is infected with a virus, but in some instances, cases have been linked to vaccinations. RSV is a common virus that causes cold-like symptoms but can be particularly dangerous for infants and the elderly. Last year, the CDC approved a recommendation for RSV vaccination for individuals aged 60 and older, offering two options developed by Pfizer and GSK.

Prior to the vaccines' approval, instances of Guillain-Barre had already been identified in clinical trials. Various monitoring systems were put in place to detect any signs of problems. During the expert panel meeting, CDC officials presented an analysis of the reports gathered by these systems. Approximately two-thirds of the Guillain-Barre cases occurred in individuals who received the Pfizer vaccine known as Abrysvo. However, officials are also conducting follow-up tracking for those who received the GSK vaccine named Arexvy.

Health officials estimate that around two cases of Guillain-Barre may occur per one million vaccine recipients. The CDC analysis revealed a lower rate for the GSK vaccine, but recipients of the Pfizer shot reported 4.6 cases per million. Data from the U.S. Food and Drug Administration also indicated a higher-than-expected number of Guillain-Barre cases among RSV vaccine recipients, especially those who received the Pfizer vaccine.

Dr. Tom Shimabukuro, a CDC vaccine safety monitoring official, stated that the available data suggests a potential increased risk for Guillain-Barre in recipients of RSV vaccines aged 60 and older, emphasizing the need for further exploration. Representatives from Pfizer and GSK acknowledged the complexity of sorting out a safety signal and affirmed their commitment to continuously monitoring and evaluating vaccine safety.

In spite of the potential risks, CDC officials highlighted that the vaccines have already prevented thousands of hospitalizations and hundreds of deaths caused by RSV. They contend that the current data indicates the benefits of vaccination outweigh the possible risks. As investigations continue, health officials aim to gather more evidence and information to make informed decisions regarding the safety and efficacy of RSV vaccines.

The findings and ongoing investigations serve as a reminder of the rigorous evaluation and monitoring processes in place to ensure the safety of vaccines. The CDC, along with other health agencies, remains committed to providing the public with accurate and up-to-date information to make informed decisions about their health.