European pharma heavyweights Sanofi and GSK announced Friday that their experimental Covid-19 vaccine will be delayed until late 2021, following a disappointing set of results from early stage clinical trials that showed a poor immune response in older adults.
- The companies said early stage clinical trials “showed an immune response comparable to patients who recovered from Covid-19 in adults aged 18 to 49 years, but a low immune response in older adults.”
- Sanofi and GSK said this was “likely due to an insufficient concentration of the antigen” in the vaccine, which is the ingredient that provokes an immune response from the body.
- The companies are now planning further tests to “refine the concentration of antigen in order to provide high-level immune response across all age groups,” and expect the vaccine to be available in the fourth quarter of 2021 at the earliest.
- Thomas Triomphe, who heads Sanofi Pasteur, the company’s vaccines division, said that while the company is obviously “disappointed by the delay… all our decisions are and will always be driven by science and data.”
- Roger Connor, president of GSK’s vaccines arm, said that while “the results of the study are not as we hoped,” he has confidence in the vaccine systems the companies are using, which have proven successful against influenza (flu) in the past, while he pledged to work with Sanofi closely to “develop this vaccine… to make a meaningful contribution to preventing Covid-19.”
Though there have been a number of big vaccine success stories in recent weeks, including the approval of Pfizer-BioNTech’s vaccine for emergency use in the U.K. and Canada, this announcement will come as a big blow to the global fight against Covid-19. Sanofi and GSK are major players in the vaccine business — developing the Covid-19 vaccine off the back of their work on the flu — and their candidate was considered one of the most promising in development that also happened to be stable at higher temperatures and rely on tried and tested technology. Even if other vaccines are approved, supplies will be short, making it essential that multiple vaccines are on the market. Sanofi and GSK were expected to be a major supplier, with arrangements in place for hundreds of millions of doses in the U.S., the EU, and the U.K..
The news of the delay comes as a blow in spite of recent successes, something both executives recognize. “It is… clear that multiple vaccines will be needed to contain the pandemic,” Connor said. Triomphe concurred: “No single pharma company can make it alone; the world needs more than one vaccine to fight the pandemic” Triomphe said.