Bivalent COVID Vax Gets Phase III Win Against Omicron, Companies Say

— Sanofi, GSK boast of 72% efficacy against Omicron variant

MedicalToday
A photo of a vial of COVID-19 vaccine with the Sanofi and GSK logos on the label.

A bivalent adjuvanted COVID-19 vaccine that targets Beta and the original coronavirus strains demonstrated high efficacy against the highly contagious Omicron variant, .

In stage 2 of their phase III study, which included 13,000 adults, the bivalent protein-based shot showed an efficacy of 64.7% (95% CI 46.6-77.2) against any symptomatic case of COVID-19 and 72% (95% CI 45.8-86.6) against Omicron-confirmed cases specifically, according to the companies.

Among those with previous SARS-CoV-2 infections, the shot had an overall efficacy of 75.1% (95% CI 56.3-86.6) and 93.2% (95% CI 73.2-99.2) versus Omicron.

"Today's results reinforce the strong potential for the Beta antigen to confer broad protection against multiple strains that cause COVID-19," Thomas Triomphe, executive vice president of vaccines at Sanofi, said in a statement. "With the from our Beta-booster vaccine, they support our belief that, in a largely seropositive world, a next-generation Beta booster vaccine could provide protection against variants like Omicron."

Stage 2 of the so-called included 13,000 individuals ages 18 and over who received the protein-based bivalent vaccine targeting the D614 (ancestral) and Beta (B.1.351) strains or placebo. Each was given in two injections 3 weeks apart. Sequencing to determine the SARS-CoV-2 strain was performed for 71 out of the 121 total COVID cases observed to date during the study.

According to Sanofi and GSK, the vaccine candidate had a favorable safety profile in stages 1/2 of the trial, which included about 23,000 individuals all told. ( tested a monovalent version of the vaccine versus placebo.)

"These positive data show efficacy of our protein-based, bivalent adjuvanted vaccine candidate in an environment of high Omicron variant circulation," said Roger Connor, president of GSK's vaccine division. "We are looking forward to the discussions with regulatory authorities with the aim of making our vaccine candidate available later this year."

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    Ian Ingram is Managing Editor at and helps cover oncology for the site.