Sanofi-GSK first to report a successful efficacy study against Omicron with COVID-19 Beta-containing vaccine

For media and investors only

Issued: London UK

  • Primary vaccination with Beta-containing vaccine candidate delivers 64.7% efficacy against symptomatic infection in adults, and 75.1% efficacy in participants previously infected with COVID-19
  • Against Omicron, sequencing analysis performed to date shows 72% efficacy in all adults and 93.2% in seropositives
  • Favorable safety and tolerability profile
  • First ever reported efficacy data in an Omicron environment support relevance of a Beta-containing vaccine

GSK plc (LSE/NYSE: GSK) and Sanofi today announce positive data from their vaccine trial which evaluated an adjuvanted bivalent D614 and Beta (B.1.351) vaccine candidate. Sanofi-GSK’s vaccine is the first candidate to demonstrate efficacy in a placebo-controlled trial in an environment of high Omicron variant circulation. The vaccine candidate showed a favorable safety and tolerability profile.

Earlier this month Sanofi reported positive data from two trials conducted with its new next-generation COVID-19 booster vaccine candidate modelled on the Beta variant antigen and including GSK’s pandemic adjuvant. Taken together, these data strongly indicate the potential of Sanofi-GSK’s next-generation Beta-based booster to be a relevant response to public health needs.

In Stage 2 of the Phase 3 COVID-19 vaccine trial VAT08 of more than 13,000 participants 18 and above years of age, the Sanofi-GSK Beta-containing vaccine candidate demonstrated an efficacy of 64.7% (95% confidence interval [CI, 46.6, 77.2]) against symptomatic COVID-19 and 72% efficacy (95% confidence interval [CI, 45.8, 86.6]) in Omicron-confirmed symptomatic cases (sequencing was performed for 71 cases out of 121 total cases to date).

In previously seropositive populations, the Sanofi-GSK vaccine candidate demonstrates an overall efficacy of 75.1% (95% confidence interval [CI, 56.3, 86.6]) against symptomatic infection, and 93.2% (95% confidence interval [CI, 73.2, 99.2]) in Omicron-confirmed symptomatic cases, according to the sequencing analysis performed to date.

Throughout Stage 1 and Stage 2 of the VAT08 trial (~23,000 participants in total), the Sanofi-GSK vaccine demonstrated a favorable safety and tolerability profile.

Thomas Triomphe, Executive Vice President Vaccines, Sanofi, said: “Today’s results reinforce the strong potential for the Beta antigen to confer broad protection against multiple strains that cause COVID-19. With the immunogenicity data 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. mRNA has proven speed to market; we are demonstrating here the efficacy that our recombinant protein platform can provide to the world. We look forward to completing our submissions to regulatory authorities and are ready to contribute to ongoing vaccination campaigns with our next-generation booster.”

Roger Connor, President of GSK Vaccines, said: “These positive data show efficacy of our protein-based, bivalent adjuvanted vaccine candidate in an environment of high Omicron variant circulation. Our vaccine candidate has the potential to make an important contribution to public health as the pandemic evolves further. We are looking forward to the discussions with regulatory authorities with the aim of making our vaccine candidate available later this year.”

These efforts are supported by federal funds from the Biomedical Advanced Research and Development Authority, part of the office of the Assistant Secretary for Preparedness and Response at the U.S. Department of Health and Human Services in collaboration with the U.S. Department of Defense Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense under Contract # W15QKN-16-9-1002 and by the National Institute of Allergy and Infectious Diseases (NIAID). The NIAID provides grant funding to the HIV Vaccine Trials Network (HVTN) Leadership and Operations Center (UM1 AI 68614HVTN), the Statistics and Data Management Center (UM1 AI 68635), the HVTN Laboratory Center (UM1 AI 68618), the HIV Prevention Trials Network Leadership and Operations Center (UM1 AI 68619), the AIDS Clinical Trials Group Leadership and Operations Center (UM1 AI 68636), and the Infectious Diseases Clinical Research Consortium (UM1 AI 148684, UM1 AI 148450, UM1 AI 148372 , UM1 AI 148574).

About the Sanofi and GSK partnership
In the collaboration between the two companies, Sanofi provides its recombinant antigen and will be the marketing authorization holder. GSK contributes with its pandemic adjuvant, both established vaccine platforms that have proven successful against influenza.

About GSK
GSK is a science-led global healthcare company. For further information please visit

Cautionary statement regarding forward-looking statements
GSK cautions investors that any forward-looking statements or projections made by GSK, including those made in this announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Such factors include, but are not limited to, those described in the Company's Annual Report on Form 20-F for 2021, GSK’s Q1 Results for 2022 and any impacts of the COVID-19 pandemic.


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