Rédaction Africa Links 24 with Helen Branswell
Published on 2024-02-29 19:58:29
The latest data from the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) suggest a potential small increased risk of developing Guillain-Barré syndrome (GBS) linked to the new vaccines that protect older adults against respiratory syncytial virus (RSV). The Advisory Committee on Immunization Practices met to discuss the findings of vaccine safety experts from both agencies, who presented data indicating a possible elevated rate of GBS among individuals who received the Pfizer RSV vaccine, with some cases also detected among those who received the GSK product.
However, it is essential to note that it is still early to determine if there is a true increased risk of developing GBS after RSV vaccination, or to quantify the size of that risk, if it indeed exists. Tom Shimabukuro, the former director of the CDC’s immunization safety office, emphasized the limitations of the current data and the need for further analysis to establish a more accurate assessment of the potential risk.
GBS is a neurological condition characterized by muscle weakness and paralysis, with most individuals recovering over time but some experiencing permanent nerve damage. While some vaccines have been associated with an increased risk of GBS, determining a definitive link between a vaccine and GBS can be challenging. The early data on GBS cases following RSV vaccination indicate the need for a more in-depth analysis, which the CDC plans to conduct using a different vaccine safety database in the coming months.
The CDC’s analysis revealed a total of 23 verified cases of GBS among approximately 9.5 million individuals who received either the Pfizer or GSK RSV vaccines. The rate of GBS cases within 21 days after vaccination was 4.6 per 1 million doses for Pfizer recipients and 1.1 per 1 million for GSK recipients, compared to an expected background rate of 2.0 cases per 1 million doses for vaccines not associated with an increased GBS risk.
Both Pfizer and GSK are actively monitoring the safety of their vaccines and conducting post-marketing studies to assess the risk of GBS among recipients. Despite the potential risk, CDC vaccine experts maintain that the benefits of RSV vaccination for individuals aged 60 and older outweigh the risks, given the burden of RSV disease in that population.
The discussion around RSV vaccines comes at a time when GSK aims to expand the license for its vaccine to include individuals aged 50 to 59 at increased risk of severe illness from RSV. The ACIP’s RSV work group is also considering revising the CDC’s recommendation on who should receive an RSV vaccine, to provide clearer guidance to healthcare providers and enhance vaccine uptake among eligible individuals.
