GSK, Sanofi say their COVID-19 vaccine won’t be ready until late 2021

A nurse prepares a shot of the Pfizer-BioNTech COVID-19 vaccine in London.
(Associated Press)
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Drugmakers GlaxoSmithKline and Sanofi say that their potential COVID-19 vaccine won’t be ready until late next year as they seek to improve the shot’s efficacy in older people.

The companies said Friday that early-stage trials showed the vaccine produced an “insufficient” immune response in older adults, demonstrating the need to refine the product so that it protects people of all ages. They said they now expect the vaccine to be available in the fourth quarter of 2021.

“The results of the study are not as we hoped,” Roger Connor, president of GSK Vaccines, said in a statement.


As researchers around the world race to develop COVID-19 vaccines, the setback announced by GSK and Sanofi shows the challenges scientists face in trying to condense a process that usually takes years into a matter of months. Researchers in Australia said Friday they were abandoning their own vaccine candidate because it produced false positive results to HIV tests.

Public health experts say several vaccines will be needed to end the pandemic, which has killed more than 1.5 million people worldwide, because of the challenges in rapidly producing and distributing enough doses to vaccinate billions of people.

A vaccine produced by Pfizer and German partner BioNTech has been authorized for widespread use in Britain — which began a mass-vaccination program Tuesday — and a handful of other countries. An FDA government advisory panel Thursday endorsed use of the Pfizer vaccine, putting the U.S. one step away from launching its own mass-vaccination program.

An influential panel of independent scientists advised the Food and Drug Administration to authorize the COVID-19 vaccine developed by Pfizer Inc. and BioNTech.

Dec. 10, 2020

GSK and Sanofi, based in London and Paris, respectively, said they were confident of their vaccine’s ultimate success because of positive results from other tests.

In adults 18 to 49, the vaccine produced an immune response comparable to patients who had recovered from COVID-19, the companies said. In addition, they reported positive results from a “challenge study” in which non-human primates were intentionally exposed to the virus.

“Following these results and the latest encouraging new preclinical data, we will now work to further optimize our candidate to achieve this goal,” Thomas Triomphe, head of Sanofi’s vaccine unit, said in a statement. “No single pharma company can make it alone. The world needs more than one vaccine to fight the pandemic.”


Researchers at the University of Queensland in Australia and the Australian biopharmaceutical company CSL said Friday that they would not move forward with their vaccine candidate because a protein in the shot triggered false positive results for HIV. Follow-up tests confirmed that no HIV was present, the researchers said.

The vaccine had proven safe and produced a “robust response” to COVID-19 during Phase 1 trials, researchers said in a statement. While it would have been possible to re-engineer the vaccine to avoid the problem with false positives, this would have taken too much time in the midst of the pandemic, they said.

“Doing so would set back development by another 12 or so months, and while this is a tough decision to take, the urgent need for a vaccine has to be everyone’s priority,” said professor Paul Young, co-leader of the project.