A 50-microgram dose of Moderna's new vaccine doubled the antibodies against the omicron variant six months after administration.
that the U.S. has until June to decide whether new Covid shots that target mutations are needed ahead of an expected fall wave of infection.
However, some FDA committee members were skeptical that new shots are needed right now, noting that the current vaccines remain effective at preventing severe illness. Federal officials told the committee that Moderna, Pfizer and other vaccine makers are not currently coordinating their clinical studies on redesigned shots, which could complicate the process of selecting the most effective vaccine for the fall.
Several FDA committee members said public health authorities need to develop a unified approach to adopting a new formula for the Covid vaccines, similar to the process for selecting new flu shots every year to target the strain that is circulating the most. "At some level, the companies kind of dictate the conversation here," Dr. Paul Offit, a committee member, said during the April 7 meeting."You often hear that the company now has an omicron-specific vaccine, or vaccine they can now link with the influenza vaccine. It shouldn't come from them, it really has to come from us."
However, developing new shots to target Covid mutations could prove challenging, given how quickly the virus is evolving. Trevor Bedford, a virologist at the Fred Hutchinson Cancer Research Center, told the FDA committee that the Covid virus is evolving two to 10 times faster than the flu, depending on which strain of the latter virus is used for comparison.