On June 15, a Food and Drug Administration (FDA) advisory committee suggested updating COVID-19 vaccines. Currently “bivalent," the vaccines target multiple variants. Following the World Health Organization's (WHO) May announcement, FDA advisers now recommend vaccinating against XBB variants starting this fall.

Currently, available COVID-19 vaccines are bivalent—meaning the vaccine targets the original COVID-19 variant and another variant. 

In April, a vaccine committee from the Centers for Disease Control and Prevention (CDC) reaffirmed the use of bivalent vaccines. However, the committee planned to revisit their recommendations later. 

FDA advisory panel and an advisory group for the World Health Organization now recommend a “monovalent” vaccine for the fall. This means the shot will target only one COVID-19 variant, XBB.1.5, and not the original variant.

XBB.1.5 is a subvariant of omicron that began to spread rapidly in the U.S. last winter. Since then, there have been multiple XBB variants (ex. XBB.1.6, referred to as “Arcturus”). Currently, different XBB variants account for about 70% of COVID-19 cases in the U.S. 

By creating a vaccine that targets XBB.1.5, advisers believe that vaccine effectiveness will improve.  

The FDA advisers did not make any recommendations on who would take the new shot and how often it would be needed.

The FDA, WHO, CDC and other agencies continue to monitor COVID-19 and COVID-19 vaccines.