Sanofi-GSK Say Their COVID Vaccine Is 100% Efficacy Against Severe Illness

Sanofi and GSK are also seeking regularity approval for use of their vaccine as universal booster doses.

Sanofi-GSK seek regulatory approval fom the US FDA, and EMA for their COVID-19 vaccine

(Photo: iStock)

A new COVID-19 vaccine developed in partnership by pharmaceutical companies Sanofi and GlaxoSmithKline (GSK) was found to be 100 percent effective in preventing severe illness and hospitalisation according to a statement released by them.

The Europe based companies have said they are seeking regulatory authorisation for their COVID-19 vaccine, not only for use as primary dose, but also as a universal booster dose post other vaccines.

In the final clinical trials, the vaccine was found to be able to boost antibody response by 18 to 30-fold after multiple vaccine platforms (mRNA, and Adenoviral vector), according to the statement.

Key Findings from the Phase 3 clinical trials:

Two doses of the vaccine in seronegative populations were found to elicit,

• 100 percent efficacy against severe disease and hospitalisations

• 75 percent efficacy against moderate to severe disease

• 57.9 percent efficacy against symptomatic illness

• 77 percent efficacy against symptomatic illness from the Delta variant (early data)

These findings apply across the dominant variants of concern.

"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."

Thomas Triomphe, Executive Vice President, Sanofi Vaccines, in a statement

Phase 1 of the global VAT08 trial was conducted on over 1000 people over the age of 18 from across the US, Asia, Africa and Latin America. This trial also included participants from India.

How Does it Work?

The Sanofi-GSK vaccine is an adjuvant recombinant protein-based COVID vaccine.

This COVID-19 vaccine uses the same technology used by GSK previously for their seasonal influenza shots.

Combining this with Sanofi's adjuvant has helped boost the vaccine's efficacy.

The vaccine can be stored in, and remains stable in regular refrigerator temperatures.

Simultaneously, in addition to this protein-based vaccine in collaboration with GSK, Sanofi is also developing an mRNA vaccine with Translate Bio Inc, that they recently acquired.

Sanofi-GSK Vaccine: Primary and Booster Doses

On top of showing a strong protection against severe illness when used for the primary doses, the vaccine also shows promise as a booster dose across vaccine platforms and age groups.

When the Sanofi-GSK vaccine was used as a booster dose after a primary two dose series of the same vaccine, neutralising antibodies increased by 84- to 153-fold, according to the companies.

The companies say they are in discussion with the US Food and Drugs Administration (US FDA), and the European Medicines Agency (EMA) for regulatory approval of their vaccine as primary vaccines, and for use as universal booster doses.

Delays and Setbacks

Back in December 2020, the companies were forced back to the drawing board when the vaccine failed to induce a strong enough immune response in participants over the age of 50 in the phase 2/3 clinical trials.

In a statement, they had said they hoped to roll out the vaccine by the end of 2021.

GSK is the largest vaccine makers in terms of sales, and has yet not been able to find its feet in the market as far as COVID-19 vaccines are concerned. The company likely hopes to change that with this vaccine.