REUTERS/Siphiwe Sibeko
- GlaxoSmithKline and Sanofi have delayed the potential rollout of their COVID-19 vaccine to the final months of 2021, after it didn’t show a strong enough response in older people.
- Interim results for human studies showed an “insufficient response in older adults,” the drugmakers said Friday — but they praised its effects in other age groups.
- The companies will repeat the early-stage studies with an improved formula in February, which will be supported by Operation Warp Speed, the White House’s vaccine effort.
- So far, the Pfizer-BioNTech vaccine is the only shot against COVID-19 that has been approved for use in the West, after being authorized in the UK and Canada earlier this month.
- In the US, the FDA is set to give its nod of approval at any time.
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A COVID-19 vaccine being developed by two of the world’s biggest vaccine makers, GlaxoSmithKline and Sanofi, has been delayed after it didn’t show a strong enough response in older people.
GlaxoSmithKline and Sanofi are now expecting potential distribution of their shot in the final months of 2021. Initially, they had expected the vaccine to be available from mid-2021.
Interim results for early-phase human studies showed an “insufficient response in older adults,” the drugmakers said in a statement Friday.
They are planning to repeat the phase-two study in February 2021 with an improved antigen formulation.
The results showed a “low immune response” in older adults, which the companies said was “likely due to an insufficient concentration of the antigen.” This is the molecule that causes an immune response.
But the drugmakers noted the efficacy of the vaccine in other age groups, saying that it "showed an immune response comparable to patients who recovered from COVID-19 in adults aged 18 to 49 years."
The most favorable results were observed in the group that had the highest antigen concentration, it added.
A pre-clinical study in monkeys using an improved antigen formulation showed the vaccine could reduce the amount of the virus in the nose and lungs. These results confirm the vaccine's "strong ability" to stop the replication of the virus with an optimal antigen formulation, the companies said.
The early phase study of 440 healthy Americans also showed "transient but higher than expected levels" of common side effects, the companies added. This was "likely due to the sub-optimal antigen formulation," they said, but no serious adverse events were reported.
The study was designed to assess the vaccine's safety, side effects, and immune response. The participants received one or two doses of the vaccine, or placebo, 21 days apart. Full results will be published when all data is available.
Under proposals, GlaxoSmithKline and Sanofi plan to compare their vaccine with an authorized shot during the second stage two study, which will be supported by the US Biomedical Advanced Research and Development Authority (BARDA) as part of Operation Warp Speed.
The new study will be followed by a global final-phase study, which could start as early as the second quarter. Depending on the results, the companies hope to submit the vaccine for authorization in the second half of 2021, which could make roll-out possible in the final quarter of the year.
Initially the companies had expected the vaccine to be available from mid-2021.
The companies are "disappointed" by the delay, Thomas Triomphe, executive vice president of French drugmaker Sanofi, said, but noted they "remain confident and committed to bringing a safe and efficacious COVID-19 vaccine."
"No single pharma company can make it alone; the world needs more than one vaccine to fight the pandemic," he added.
Millions of doses of GlaxoSmithKline and Sanofi's vaccine have been pre-ordered as countries scramble for the shots amid climbing COVID-19 cases across the world. This includes 300 million for the EU, 60 million for the UK, and 100 million for the US, alongside an option for 500 million in total.
Covax, a World Health Organization partnership designed to share vaccine doses with lower-income countries, was to receive 200 million.
So far, the Pfizer-BioNTech vaccine is the only shot against COVID-19 that has been approved for use in the West. The UK gave the first doses on Tuesday, and Canada approved the vaccine for emergency use on Wednesday.
In the US, an expert panel of 22 leading scientists and doctors voted to endorse emergency use authorization for Pfizer's vaccine during a Food and Drug Administration (FDA) advisory committee meeting on Thursday. The FDA is set to give the final nod of approval at any time.