In a phase 2/3 study, Sanofi-GSK's next-generation COVID-19 vaccine booster resulted in 76.1 percent of participants seeing at least a tenfold increase in neutralizing antibody titers. Pfizer's booster and Sanofi-GSK's first-generation vaccine trailed behind at 63.2 percent and 55.3 percent, respectively, according to the June 13 press release.
Among 247 study participants, the vaccine booster candidate proved effective against variants of concern 15 days after immunization.
The results are pending publication in a peer-reviewed journal, and the company plans to pitch the data to regulators in a few weeks.