Fall Covid Boosters on Fast Track with Mouse Data
Covid-19 vaccine makers need to get data on their reformulated booster shots into FDA by the end of the month so they can begin administering them starting in September. But in order to expedite their authorization, FDA is permitting mouse data instead of human data to be submitted, which is a controversial strategy causing some grumbling among health experts, according to an NPR report.
The new boosters are designed to protect against omicron BA.4 and BA.5, the latter now accounting for nearly 90% of new Covid cases in the U.S., according to the CDC. The goal is to begin boosting people in September in an attempt to curb the expected increase in Covid infections this fall and winter.
“For the FDA to rely on mouse data is just bizarre, in my opinion,” Weill Cornell Medicine immunologist John Moore told NPR. “Mouse data are not going to be predictive in any way of what you would see in humans.” Other experts feel that the U.S. has had enough experience with the vaccines at this point to be confident the shots are safe, and time is short to wait for human study data.
“We have 500 people a day dying of coronavirus right now. Those numbers sadly might very well rise in the fall and the winter. The question is: ‘Can we do something better?’” asked Dr. Ofer Levy, a Harvard Medical School pediatrics and infectious disease researcher who also advises the FDA. “And I think the answer is: ‘We can, by implementing this approach.’”
FDA reviewers will rely on the mouse data, along with the human neutralizing antibody data to decide whether to authorize the boosters, according to NPR. Companies will continue to collect and analyze data from human studies, but those may not be available until late October or early November. “We need to make sure that we have solid immunogenicity data in people to show that you have a dramatically greater neutralizing antibody response against BA.4, BA.5,” FDA advisory committee member and University of Pennsylvania’s Paul Offit said. “I think anything short of that is not acceptable.”
FDA spokesman Michael Felberbaum told FDA Webview the agency "will be using the totality of the available evidence to authorize the fall bivalent boosters. There are data on many millions of individuals who have received the prototype component as a booster. As for the BA.4/5 component, a combination of nonclinical data obtained in mice, data from prior variant vaccines (including those to beta, delta, and omicron BA.1), along with our extensive knowledge of the safety and efficacy of the mRNA platforms will be used for this decision-making. This is similar to what is done for influenza vaccine strain changes."