Two pharmaceutical companies have teamed up with the hope of making a Covid-19 vaccine available by the middle of next year.

The vaccine from Sanofi and GSK, who have signed a letter of intent to collaborate, is expected to enter clinical trials in the second half of this year.

Sanofi will contribute its S-protein Covid-19 antigen, which is based on recombinant DNA technology.

This technology has produced an exact genetic match to proteins found on the surface of the virus.

GSK will contribute its pandemic adjuvant technology to the collaboration.

An adjuvant is added to some vaccines to enhance the immune response, and has been shown to create a stronger and longer lasting immunity against infections than the vaccine alone.

The use of an adjuvant can be of particular importance in a pandemic situation, as it may reduce the amount of vaccine protein required per dose.

This allows more vaccine doses to be produced.

Paul Hudson, chief executive of Sanofi, said: “As the world faces this unprecedented global health crisis, it is clear that no one company can go it alone.

“That is why Sanofi is continuing to complement its expertise and resources with our peers, such as GSK, with the goal to create and supply sufficient quantities of vaccines that will help stop this virus.”

Emma Walmsley, chief executive of GSK, said: “By combining our science and our technologies, we believe we can help accelerate the global effort to develop a vaccine to protect as many people as possible from Covid-19.”

The companies plan to initiate phase I clinical trials in the second half of 2020 and, if successful and subject to regulatory considerations, aim to complete the development required for availability by the second half of 2021.