FRENCH drugmaker Sanofi SA plans to enroll thousands of subjects globally for trials of an experimental vaccine for the coronavirus it is developing with GlaxoSmithKline Plc (GSK) and it has started to discuss advanced purchases with several countries.

Sanofi is working on two vaccine projects to prevent COVID-19, the illness caused by the new coronavirus, and said it is exploring several manufacturing options, including fresh collaborations to ensure it can meet demand, if either program is successful.

Drugmakers are rushing to develop treatments and vaccines for the highly contagious coronavirus that has killed over 255,000 people worldwide, infected more than 3.6 million and ravaged economies globally.

Of more than 100 vaccine candidates in development, 10 have reached the clinical testing stage so far, according to California-based think tank Milken Institute.

Sanofi, whose Pasteur division has an established track record in influenza vaccines, teamed with British rival GSK last month to come up with a candidate it hopes will be ready next year.

Sanofi will bring in a protein antigen, a molecule designed to trigger an immune response in the body, based on a platform it uses for its influenza vaccine Flublok.

GSK will contribute one of its approved adjuvants, which work by boosting the immune response to produce more antibodies and longer-lasting immunity.

Sanofi Pasteur executives said the company hopes to start early-stage trials in September, with hundreds of subjects enrolled.

While Phase I vaccine trials typically involve a small number of healthy volunteers to test for safety, Sanofi said it had opted for higher numbers to secure stronger data sooner.

“We envisioned Phase I to actually have several hundreds of subjects, so it is really a phase I/II trial,” said John Shiver, head of Sanofi vaccine research.

Beyond finding the right vaccine, a key challenge lies in manufacturing on an enormous scale and distributing the product globally. (SD-Agencies)