AstraZeneca Vaccine Not Likely to Receive U.S. EUA Until April, Warp Speed Chief Says
The United Kingdom authorized AstraZeneca’s COVID-19 vaccine on Wednesday, but it could be April at the earliest before the drug will likely be administered in the United States, Operation Warp Speed’s chief said.
During a call with reporters following the U.K. approval, Moncef Slaoui, head of the government’s effort to support the development of COVID-19 vaccine programs, pointed to questions about the amount of protection the vaccine could provide to the elderly, as well as conflicting efficacy reports of the vaccine developed by AstraZeneca and Oxford University. Those concerns have pushed back expected Emergency Use Authorization (EUA) of the AstraZeneca vaccine by two months.
This morning, Politico reported Slaoui predicted AstraZeneca’s vaccine will not be authorized until those questions can be answered. During a press call Wednesday, Slaoui said the known efficacy of the AstraZeneca vaccine is solid and appears effective against severe diseases. However, he went on to note that the vaccine’s efficacy is “effectively unknown” in elderly patient populations, which are among the most vulnerable to coronavirus infection. During clinical studies, AstraZeneca did not include enough of that patient population to provide enough evidence about the benefits that medication will have.
AstraZeneca’s COVID-19 vaccine candidate AZD1222 is a viral vector-based, weakened version of adenovirus containing the genetic material of SARS-CoV-2 spike protein. AstraZeneca’s efficacy is at 70.4%. During Phase III trials, one of the cohorts was administered one and a half doses, as opposed to two full doses. Vaccine efficacy in that cohort was up to 90%. The disparity is under investigation by the researchers. In interviews ahead of the U.K. authorization, AstraZeneca Chief Executive Officer Pascal Soriot expressed confidence the level of protection provided by his company’s vaccine will be close to that of the mRNA vaccines developed by Moderna and Pfizer and BioNTech, which demonstrated 94% and 95% efficacy, respectively.
While the 70% efficacy is well above the threshold set by the U.S. Food and Drug Administration for a COVID-19 vaccine, Slaoui, the former head of vaccine development at GlaxoSmithKline, suggested that U.S. regulators would not be satisfied by that conclusion, Politico reported.
“As far as the American people are concerned, I think it’s important to say one vaccine has 95 percent efficacy, another vaccine has X percent, whatever that number,” Slaoui said in reference to the efficacy ratings for the Moderna vaccines that have already received Emergency Use Authorization from the FDA. “We need a clear and concrete number more than a number that is accumulated by adding together different trials with different schedules and different materials.”
AstraZeneca indicates it expects to have capacity to manufacture up to 3 billion doses in 2021 on a rolling basis. Its vaccine could have a greater reach than the mRNA vaccines due to less stringent conditions required for storage and transport.
While AstraZeneca’s vaccine may not be used in the U.S. until spring, Johnson & Johnson could be in line to offer the third vaccine authorized in the United States. Earlier this month, the company said its Phase III ENSEMBLE study is fully enrolled with 45,000 participants. Interim data from the ENSEMBLE trial is currently anticipated to be available by the end of January. If the data indicate the vaccine is safe and effective, the company expects to seek EUA from the FDA in February.
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