Sanofi will invest about €400m in research and development of next-generation vaccines using mRNA technologies, which proved their efficiency in the Pfizer and Moderna Covid-19 vaccines.

The French drug giant and its British counterpart GlaxoSmithKline surprised investors and customers late last year when they announced a one-year delay to the launch of their joint Covid vaccine, based on a more conventional technology.

Sanofi has since pledged to help Pfizer and Moderna manufacture Covid-19 shots in an effort to help meet the huge demand for the US drugmaker's doses.

Sanofi said today that its "mRNA Center of Excellence" will bring together around 400 employees, and was expected to produce a minimum of six clinical candidates by 2025.

"During the Covid-19 pandemic, mRNA technologies demonstrated potential to deliver new vaccines faster than ever before", said Jean-Francois Toussaint, global head of R&D at Sanofi Pasteur.

"However, key areas of innovation such as thermostability and tolerability improvements will be critical to unlock the applications of mRNA in routine vaccination against a broader set of infectious diseases and across all ages," he added.

The mRNA technology has proven both effective and safe so far in the vaccine response to Covid-19, including in response to the virus' variants.

The latest one, the Delta variant first found in India, is spreading at a fast rate around the world, prompting governments to accelerate their vaccinations programmes.

Sanofi is also working on a mRNA Covid-19 vaccine candidate with US company Translate Bio, for which it has started clinical trials.

The two groups, which have been collaborating since 2018, have also started a Phase I clinical trial earlier this year evaluating an mRNA-based investigational vaccine against seasonal influenza.

Last month, Sanofi and GlaxoSmithKline launched a late-stage human trial for a recombinant Covid-19 vaccine candidate, which they hope to get approved by the end of 2021.

That vaccine is based one of the most established technologies in vaccines - used against the human papillomavirus, hepatitis B and pertussis among other pathogens - which aims to introduce lab-made proteins into the body to prod the immune system into developing a targeted defence against the coronavirus.