Two doses of a new COVID-19 vaccine from Sanofi and GSK were 100% effective against severe disease and hospitalizations, the companies announced Wednesday.

The vaccine was also 75% effective against moderate-to-severe disease and 58% effective against symptomatic disease in a Phase 3 clinical trial.

And when used as a booster dose after one of the other available COVID-19 vaccines, the new vaccine triggered an 18- to 30-fold increase in antibody levels, the companies said in a statement.

“We’re very pleased with these data, which confirm our strong science and the benefits of our COVID-19 vaccine, said Thomas Triomphe, executive vice president of Sanofi Vaccines.

“The Sanofi-GSK vaccine demonstrates a universal ability to boost all platforms and across all ages,” he said in the statement. “We also observed robust efficacy of the vaccine as a primary series in today’s challenging epidemiological environment. No other global Phase 3 efficacy study has been undertaken during this period with so many variants of concern, including Omicron, and these efficacy data are similar to the recent clinical data from authorized vaccines.”

In laboratory studies, two doses of the Sanofi-GSK vaccine stimulated the production of more neutralizing antibodies than an approved mRNA vaccine, the companies noted.

The data have not yet been published.

The vaccine was safe and well-tolerated by adults of all ages, according to the companies. They said they plan to submit the vaccine for emergency authorization to regulatory authorities in the United States and Europe.

The Sanofi-GSK vaccine uses a slightly modified version of the protein itself to stimulate an immune response, a commonly used method of making vaccines.

It was one of four candidates that received billions of dollars for development from Operation Warp Speed, the Trump administration’s program to accelerate vaccines. The companies were expected to seek authorization for their vaccine last year, but clinical trials showed disappointing results in older adults. So the companies then developed a stronger version of the vaccine and tested it in new trials, the New York Times reported.

Last month, Novovax applied to the U.S. Food and Drug Administration for emergency authorization of a similar protein-based COVID-19 vaccine.

Protein vaccines are relatively inexpensive and may not require the ultra-cold storage needed for mRNA vaccines, which may make protein-based vaccines more likely to be used in Africa, where there are low vaccination rates, the Times reported.

More information

Visit the U.S. Centers for Disease Control and Prevention for more on COVID vaccines.

SOURCES: Sanofi/GSK, news release, Feb. 23, 2022; Novovax, news release, Jan. 31, 2022; New York Times

Source: HealthDay