“I can’t see why the regulator wouldn’t approve it,” Barker wrote, but cautioned that the detailed data was still outstanding.
One key question for the FDA will be what dosing regimen it will endorse should it ultimately approve the vaccine for emergency use.
“This trial is based on dosing 4 weeks apart, but we know efficacy may be greater if you dose with a longer interval (up to 12 weeks) and countries like the U.K. have successfully used this ‘longer duration between doses’ strategy to vaccinate more people quickly,” Barker said.
So the question for the FDA is whether it will recommend giving the two doses four weeks apart — given that’s what was tested in the U.S. trial — or include data from the U.K. and elsewhere that suggests a longer duration.
Welford also noted the suboptimal dosing regimen used in this trial. “The trial evaluated the 4-week dosing schedule, but we have evidence to suggest the vaccine works better with a longer dosing interval,” he said.
“Primary analysis of the Phase III clinical trials from the U.K., Brazil and South Africa showed 62% efficacy when given the vaccine was given at an interval of 4 to 12 weeks but efficacy increased to 82% when the interval was stretched to 12 weeks.”
Beyond dosing, analysts are also watching for detail on how the vaccine protects against different variants. This is expected to be included in the package of data submitted to the FDA.
When it comes to comparing today’s efficacy data to that from some of the other vaccine-makers, Welford cautioned that since the initial vaccine readouts from Pfizer and Moderna, Covid-19 variants have become increasingly common, so the efficacy data is not directly comparable across the different vaccines.
Barker added that the trial results gave the vaccine important validation. “Given its cost and ease of storage and distribution, AZD1222 was once described as a ‘vaccine for the world’. This is a fair label in our opinion,” he wrote. “Data like this reported today that more conclusively demonstrates the efficacy and safety of AZD1222 is certainly something to celebrate.”
AstraZeneca has pledged to distribute the vaccine at no profit for the duration of the pandemic. The company’s shares traded 2% higher in London on Monday.
Source Article from https://www.cnbc.com/2021/03/22/analysts-cheer-surprisingly-positive-astrazeneca-us-trial-data.html
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