GlaxoSmithKline (GSK 0.09%) and Sanofi (SNY 0.02%), two European pharmaceutical companies that are leaders in vaccines for viral diseases, announced a collaboration to develop an adjuvanted vaccine for SARS-CoV-2, the coronavirus that causes COVID-19. If the vaccine succeeds in clinical trials scheduled to start later this year, it could be available in the second half of 2021.

Sanofi will contribute a COVID-19 antigen that's based on its recombinant DNA technology. The company has produced an exact genetic match to proteins found on the surface of the virus, which are combined into the DNA of a baculovirus to create the antigen. Sanofi is using the technology in its quadrivalent flu vaccine Flublock; it obtained that product and the recombinant DNA platform through its acquisition of Protein Sciences in 2017.

Several coronavirus cells.

Image source: Getty Images.

GlaxoSmithKline will contribute its adjuvant technology to the vaccine. Adjuvants are chemical additives combined with vaccines that stimulate the body's immune system, causing it to produce a stronger response to the antigen. That means that a smaller amount of vaccine protein is required for each dose, so more vaccine doses can be produced in less time. GSK's adjuvant technology is a major reason for the success of its Shingrix shingles vaccine.

Both companies are taking multiple shots on the COVID-19 goal. Sanofi also makes hydroxychloroquine, a malaria drug that is being tested as a possible treatment for the disease. It has announced it will donate 100 million doses of it to 50 countries to be used in the fight against the pandemic. It's also working with Regeneron (REGN 0.41%) to test an existing arthritis drugKevzara, as a possible treatment, and has partnered with Translate Bio (TBIO) to develop a SAR-CoV-2 vaccine based on messenger RNA. GlaxoSmithKline is also contributing its adjuvant technology to COVID-19 vaccine candidates being developed by other companies, including Chinese biotech Clover Biopharmaceuticals and immunology specialist Vir Biotechnology (VIR -3.95%).