Sanofi and GlaxoSmithKline (GSK) announced Friday a delay in their COVID-19 vaccine program after study results found older patients failed to demonstrate a sufficient immune response against the coronavirus.
The companies said in a joint statement the low immune response was likely due to an insufficient concentration of the antigen, which triggers the immune system to create antibodies to fight the coronavirus.
“The results of the study are not as we hoped,” Roger Connor, president of GSK Vaccines, said in the press release. “Our aim now is to work closely with our partner Sanofi to develop this vaccine, with an improved antigen formulation, for it to make a meaningful contribution to prevention COVID-19.”
Phase 1/2 trial interim results found participants between 18 and 49 years old showed an immune response comparable to patients who recovered from COVID-19. In addition, they reported positive results from a “challenge study” in which non-human primates were intentionally exposed to the virus.
The U.S. government made a $2.1 billion deal with Sanofi/GSK to test and produce 100 million doses of the vaccine under Operation Warp Speed. The majority of the money will go to Sanofi, which made the vaccine candidate. GSK made a booster that improves how the body responds to it.
A Sanofi spokesperson told USA TODAY doses were only produced for the Phase 1/2 trial and the company is in the process of producing the improved formulation for the upcoming Phase 2b trial, which will start in February.
The company doesn’t expect its deal with Operation Warp Speed to change based on Friday’s news, and projects doses may be available to the public at the end of next year, pending the improved vaccine’s success.
“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 the press release. “No single pharma company can make it alone. The world needs more than one vaccine to fight the pandemic.”
While researchers around the world are racing to develop COVID-19 vaccines, the setback announced by Sanofi and GSK shows the challenges scientists face as they try to condense a process that usually takes years into a matter of months.
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Researchers in Australia said Friday they were abandoning their own vaccine candidate from the University of Queensland and biopharmaceutical company CSL because it produced false positive results for HIV. Follow up tests confirmed that no HIV was present, the researchers said.
While it would have been possible to re-engineer the vaccine to avoid the problem with false positives, it would have taken too much time in the midst of the pandemic, they said.
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 U.S. drugmaker Pfizer and German partner BioNTech has been authorized for widespread use in the United Kingdom and a handful of other countries. A U.S. government advisory panel on Thursday endorsed use of the Pfizer vaccine, putting the country one step away from launching its own mass vaccination program.
Health and Human Services Secretary Alex Azar said Friday on ABC’s “Good Morning America” that the U.S. Food and Drug Administration is expected to grant emergency use authorization for the vaccinesoon.
“We could see people getting vaccinated Monday, Tuesday of next week,” Azar said.
Contributing: Associated Press. Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT.
Health and patient safety coverage at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide editorial input.
This article originally appeared on USA TODAY: COVID vaccine: Sanofi, GSK announce delay, doses expected end of 2021