Studies on the COVID-19 vaccine candidate from AstraZeneca and Oxford University suggest that it is safe and about 70 percent effective on average, though some questions remain.
The partial results published in The Lancet on Tuesday confirmed that the two full doses given at least one month apart appeared to be 62 percent effective, while a half dose followed by a full dose was about 90 percent effective.
AstraZeneca and Oxford first announced the efficacy results of their vaccine late last month. The findings later came under scrutiny after the company acknowledged that members of a sub-group of trial participants were originally mistakenly given a half dose followed by a full dose.
The admission, along with a relatively small test group compared to other studies, drew questions among experts on the accuracy of the findings.
The Lancet's interim analysis published Tuesday focused on studies of the vaccine in the U.K., Brazil and South Africa, with efficacy data on 11,636 participants reported.
Independent experts have noted that the second group, which was given a half dose followed by a full dose, was too small to judge the value of that dosing strategy, The Associated Press reported.
The AP also noted that the half-dose group did not include those over the age of 55, which has become a key health concern for health officials around the world.
AstraZeneca CEO Pascal Soriot has said the company would likely conduct another global trial of the vaccine using the half dose followed by the full one.
Soriot said in a statement on Tuesday that the publication of the data “enables a full disclosure” on the analysis.
“We have begun submitting data to regulatory authorities around the world for early approval and our global supply chains are up and running, ready to quickly begin delivering hundreds of millions of doses on a global scale at no profit,” he said.