Dr. Peter Marks, head of the FDA office responsible for vaccine safety, indicated this week that the U.S. might need to offer fourth shots for people under 50-years-old in the fall.
People who are now eligible for fourth shots would likely get a fifth shot if there’s evidence that would be beneficial, Marks told reporters on a conference call.
Marks also said the U.S. could switch to a different COVID-19 vaccine that targets a specific variant of SARS-CoV-2 or a mix of several. The current COVID-19 vaccines were developed against the original Wuhan virus.
Pfizer and Moderna are conducting clinical trials on COVID-19 booster shots that target both Omicron and other circulating variants of SARS-CoV-2.
“It would not be surprising if there is a potential need for people to get an additional booster in the fall along with a more general booster campaign if that takes place,” Marks said. “It may be that a decision is made that rather than the vaccines we currently have, which are called vaccines against the prototype virus, that we will move to a vaccine that is either against one of the variants or something else.”