AstraZeneca says the COVID-19 vaccine it developed in cooperation with Oxford University was 79-percent effective in preventing symptomatic illness a large trial in the United States, Chile and Peru, paving the way for its long-awaited application for US approval.
The vaccine was found to be 100 percent effective against severe or critical disease and hospitalisation and was safe, the drug maker said on Monday, as it released results of the late-stage human trial study of more than 32,000 volunteers across all age groups.
The study found the vaccine effective across all ages, including older people, which previous studies in other countries had raised concerns over.
Although AstraZeneca’s vaccine has been authorised in more than 50 countries, it has yet to receive the green light in the US.
This will also help allay safety concerns that disrupted its use in the European Union after a small number of cases of rare blood clots in people who have received the shot were reported.
After more than two dozen countries briefly halted its use, many European countries have resumed using the shot in their inoculation programmes after a regional regulator said it was safe, while several country leaders are also taking the vaccine to boost confidence.
AstraZeneca said an independent safety committee conducted a specific review of the blood clots in the US trial, as well as cerebral venous sinus thrombosis (CVST), which is an extremely rare blood clot in the brain, with the help of an independent neurologist.
The London-listed company said the panel found “no increased risk of thrombosis [the process of a blood clot forming] or events characterised by thrombosis among the 21,583 participants receiving at least one dose of the vaccine. The specific search for CVST found no events in this trial”.
The data will be prepared to apply for approval from the US Food and Drug Administration (FDA), University of Oxford professor Sarah Gilbert told BBC radio. The preparation will take a few weeks, she added.
The US has ordered 300 million doses of the vaccine, and has faced pressure to share doses manufactured domestically before the FDA’s approval.
The White House last week said the US currently had 7 million “releasable doses” of the vaccine, and that it was working out deals to “loan” 2.5 million doses to Mexico and 1.5 million doses to Canada in the near future.