Britain's AstraZeneca PLC said Monday its coronavirus vaccine was 79 percent effective in preventing the disease caused by the novel coronavirus in a clinical trial conducted in the United States and two South American countries.
It also said experts have identified no safety concerns related to the vaccine, including any increased risk of blood clots. Blood clots among those who received the shots have been reported in Europe, leading France and other countries to temporarily suspend use of the AstraZeneca vaccine.
The biopharmaceutical company said it is preparing to seek emergency use authorization from the U.S. drug regulator in the "coming weeks."
The AstraZeneca vaccine has already been approved for use in more than 70 countries around the world.
According to an interim analysis of the U.S. trial that involved around 32,000 participants, the vaccine showed 79 percent efficacy in preventing symptomatic COVID-19, the respiratory illness caused by the coronavirus, and 100 percent efficacy in preventing severe disease and hospitalization.
Protection was consistent across ethnicity and age. Notably, in participants aged 65 years and over, efficacy was 80 percent, according to the company.
Nearly 80 percent of the participants were white and 4 percent were Asian, among others.
The risk of blood clots was studied among the roughly 22,000 participants receiving at least one dose of the two-dose vaccine, the company said.
