Sanofi-GSK COVID-19 Vaccine Reports 100% Efficacy Against Severe Disease

Today, makers of a new COVID-19 vaccine announced results showing two doses achieved 100 percent efficacy against severe Covid disease and hospitalizations and could potentially be an effective booster following other vaccine doses.

The vaccine, made by the pharmaceutical companies Sanofi and GSK, reported an efficacy of 75% against moderate-to-severe disease and showed 58% efficacy against any symptomatic COVID-19 disease in the VAT08 Phase 3 trial.

Despite the efficacy being lower than what was observed for in the initial mRNA vaccines made by Pfizer-BioNTech and Moderna, the 2 companies noted it is “in line with expected vaccine effectiveness in today’s environment dominated by variants of concern.”

Further analysis of the global VAT02 booster trial confirmed the vaccine’s ability to boost neutralizing antibodies 18- to 30-fold following one of the other available Covid vaccines.

The company additionally reported neutralizing antibodies increased 84- to 153-fold when the vaccine was used as a two-dose primary series followed by a booster dose.

More data from the company show the vaccine delivered high levels of robust levels of neutralizing antibodies, with GMTs reaching 3711 units when used as a two-dose primary series. In comparison, two-doses of an already approved mRNA vaccine displayed a GMT of 1653 measured in the same laboratory.

Both the primary series and booster vaccinations showed a favorable safety profile and were well-tolerated in both younger and older adults.

“The evolving epidemiology of COVID-19 demonstrates the need for a variety of vaccines,” said Roger Connor, President of GSK Vaccines in a statement. “Our adjuvanted protein-based vaccine candidate uses a well-established approach that has been applied widely to prevent infection with other viruses including pandemic flu. We are confident that this vaccine can play an important role as we continue to address this pandemic and prepare for the post-pandemic period.”

Sanofi and GSK announced they intend to submit data from both Phase 3 trials as the basis for regulatory applications for a COVID-19 vaccine for both the US Food and Drug Administration and the European Medicines Agency (EMA).

The vaccine is one of four candidates that received funding from Operation Warp Speed, the Trump administration’s program to accelerate vaccine development.

Full study results for both VAT08 and VAT02 are expected to be published later this year.