AstraZeneca and the University of Oxford are facing criticism over their COVID-19 vaccine trial results.
According to Business Insider the criticism comes after AstraZeneca admitted to a mistake in the vaccine dosage.
During the vaccine trial, some patients got two full doses of the vaccine.
Others had a half-dose in their first shot, followed by a full dose.
On Wednesday, an AstraZeneca executive described the "mistake" as "serendipity."
The vaccine was 90% effective in the group with the initial half-dosage, compared to 62% effective in the full-dosage group.