The AstraZeneca-Oxford Covid-19 vaccine was 79% effective against stopping symptomatic Covid disease and 100% effective in preventing severe disease and hospitalizations in its U.S. Phase III trial, the drug maker said in a press release on Monday, highlighting the safety and effectiveness of the vaccine amid suspension of its use in some countries over safety concerns.
Citing independent safety monitoring of the trials, AstraZeneca said it found no increased risk of blood clots among the 21,583 participants who received at least one dose of the vaccine and no instances of cerebral blood clots were recorded in the trial.
The drug maker noted that the vaccine’s effectiveness was consistent across age groups and showed 80% efficacy in participants aged 65-years and older.
The large-scale Phase-III U.S. trials featured 32,449 participants, mostly from America but also included some participants from Chile and Peru.
Participants who received the vaccine were given two doses at a four week interval, however, AstraZeneca noted an extended interval of 12 weeks between shots has demonstrated even greater efficacy in previous trials.
Around 20% of the participants were older than 65 and 60% had comorbidities—such as diabetes, severe obesity or cardiac disease—which increase the risk of severe disease.
AstraZeneca will prepare for the primary analysis of the trial to be submitted to the U.S. Food and Drug Administration (FDA) for Emergency Use Authorization in the coming weeks.
4 million. That’s the total number of doses of the AstraZeneca vaccine the Biden administration plans to send to neighbours Mexico and Canada, White House Press Secretary Jen Psaki said last week. Although the U.S. has not yet approved the vaccine for emergency use, AstraZeneca plans to have 30 million shots ready in the country at the beginning of April.