In a 19-2 vote, FDA advisers recommended vaccine-makers to focus on updated, omicron-containing vaccines after a daylong meeting June 28.
The 21 voting members on the Vaccines and Related Biological Products Advisory Committee debated the question, "Does the committee recommend inclusion of a SARS-CoV-2 omicron component for COVID-19 booster vaccines in the United States?"
The panel weighed various considerations, including whether there's a preference between omicron subvariants, whether to focus on monovalent (containing omicron) or bivalent (containing omicron and a prototype), and whether to extrapolate the current data to other age groups since most research has focused on older populations.
After hours of deliberation, the panel did not agree to prioritize any of the six reported omicron subvariants.
Moderna's bivalent candidate boosted antibodies "5.4-fold above baseline" against omicron's "sister variants," BA.4 and BA.5, which recently became the nation's leading strains, according to CDC data. The company is preparing to deploy tens of millions of this booster this fall as it awaits authorization.
Pfizer and GSK-Sanofi are also researching omicron-focused vaccines in ongoing phase 3 trials, but before the U.S. has the option for better protection against omicron, the FDA and CDC have to greenlight the vaccine candidates. If authorized, doses are expected this fall.