MOSCOW, (Sputnik) - On Monday, AstraZeneca released interim results of its candidate vaccine showing two different levels of efficacy depending on the dosing regimen. Efficacy in patients administered two full doses one month apart was 62 percent, while in those administered a half-dose and then a full dose it reached 90 percent. The company later admitted that the regimen with higher efficacy had actually been a result of a dosing mistake.
“Now that we’ve found what looks like a better efficacy we have to validate this, so we need to do an additional study,” Soriot told Bloomberg.
While the official did not specify the country, he was quoted as saying that it would be an "international study, but this one could be faster because we know the efficacy is high so we need a smaller number of patients."
The company will "more likely" conduct trials in the United States in order to secure the vaccine's approval by the US regulator, Soriot said.
In late August, the US National Institute of Health said the AstraZeneca vaccine would be tested on 30,000 volunteers in the United States in phase 3 clinical trials. This was part of the effort of the US Health Department-led collaborative facility for the development and distribution of counter-coronavirus medical supplies, known as Operation Warp Speed.
It was the chief adviser of Operation Warp Speed, Moncef Slaoui, who revealed earlier this week that AstraZeneca's vaccine dosing regimen with higher efficacy had been tested on a lot fewer and younger people. Neither of these details had appeared in the company's previous official press releases, which only further contributed to the drop of confidence in the vaccine.