A Food and Drug Administration advisory panel voted unanimously on Thursday to issue an updated COVID-19 vaccine for the remainder of 2023 and early 2024, to be available as early as September.
The 21-person Vaccines and Related Biological Products Advisory Committee met in its fourth meeting since April 2022 on COVID-19 vaccine updates to review data and discuss whether or not the latest vaccine is effective against currently circulating strains of the virus and to predict what will become the predominant variant in the coming months.
Current mRNA vaccines produced by Pfizer-BioNTech and Moderna are bivalent vaccines that provide protection from hospitalization and death against the original Wuhan strain and Omicron BA4/BA5 strains.
Data presented at the meeting indicated that the Wuhan strain is essentially “extinct,” meaning that it is no longer circulating among the general population.
The panel recommended manufacturers begin producing monovalent vaccines targeting the XBB 1.5 strain of SARS-CoV-2. Director of the Center for Biologics Evaluation at the FDA Peter Marks told the committee that the XBB 1.5 variant would be the ideal focus of the new vaccines due to manufacturing and supply factors.
“We are not chasing variants,” said meeting chairman Arnold Monto, professor emeritus of epidemiology at the University of Michigan.
Although other variations of XBB, including XBB 1.16 and XBB 2.3, are also circulating and could become the dominant strains during the fall and winter months, members of the committee acknowledged that the similarities in the protein structure for the three prevailing XBB strains could produce similar rates of efficacy even with a specific monovalent vaccine.
“It’s not an easy choice,” said Jerry Weir, director of the Division of Viral Products at the FDA, when discussing which variant to choose for the new vaccine. “It might not even matter.”
A point of significant debate at the close of the meeting was the degree of seasonality of COVID-19 and whether or not the vaccination timeline should be perceived as similar to influenza’s seasonal pattern.
Marks told committee members, however, that public health officials “have not done a good job communicating to the American public.” He said that clarity and practicality were needed in government messaging on COVID-19 prevention.
“People need to be able to understand what we are actually doing,” said Marks.
Cody Meissner, a leading physician and expert on childhood vaccinations and infectious diseases, said that, as rates of severe disease and death from COVID-19 continue to decrease, “it is going to be difficult to convince many people to get the vaccine.”
As of May 10, the Centers for Disease Control and Prevention estimated that 81.4% of Americans have received at least one dose of the original monovalent vaccine, but only 17% of the population has received the updated bivalent booster.
Marks estimated that, based upon Thursday’s recommendations, vaccine manufacturers could begin to roll out new products in “September-ish” if manufacturing, supply, and regulatory factors stay constant.
