Beta-vax: Sanofi, GSK hail phase 3 omicron win to throw down gauntlet in COVID-19 vaccine format war

After lagging the leaders in the original COVID-19 vaccine race, Sanofi and GSK have now claimed a first in the push to protect people from omicron. The partners hailed the first successful efficacy study against omicron after their beta-specific vaccine achieved 72% protection versus the now-dominant variant.

In February, Sanofi and GSK reported their vaccine against the original SARS-CoV-2 virus achieved 58% protection from symptomatic COVID-19. Early sequencing data indicated the vaccine had 77% efficacy against the delta variant, suggesting that omicron’s immune evasion may have dragged the overall result down. By then, the partners were already looking beyond that first-generation vaccine, having recently completed enrollment in a cohort that received the bivalent beta vaccine.

Now, Sanofi and GSK have data from the 13,000-subject cohort. The vaccine, which is designed to protect against the original and beta forms of SARS-CoV-2, achieved 64.7% efficacy versus symptomatic COVID-19. Efficacy rose to 72% in omicron-confirmed symptomatic cases. Sanofi and GSK have sequenced 71 out of 121 cases to date.

Efficacy was higher in participants previously infected with COVID-19. In that subpopulation, the vaccine achieved overall efficacy against symptomatic infection of 75.1%. The efficacy figure rose to 93.2% in the group of omicron-confirmed symptomatic cases. 

With Moderna and Pfizer yet to report efficacy data on their variant-specific vaccines, it is unclear how competitive the results will prove to be. The question of the durability of efficacy remains unanswered, too. Even so, Thomas Triomphe, executive vice president of vaccines at Sanofi, used the data drop to make the case that the recombinant protein vaccine has a place in a COVID-19 market dominated to date by mRNA vaccines. 

“With the immunogenicity data from our beta-booster vaccine, [these results] support our belief that, in a largely seropositive world, a next-generation beta booster vaccine could provide protection against variants like omicron. mRNA has proven speed to market; we are demonstrating here the efficacy that our recombinant protein platform can provide to the world,” Triomphe said in a statement.

Sanofi and GSK are now preparing to submit the data to regulatory authorities with a view to coming to market later this year. The companies previously applied for conditional regulatory authorization of their first-generation COVID-19 vaccine in Europe.