Although AstraZeneca’s vaccine has been authorized in more than 50 countries, including Canada, it has yet to be given the green light in the United States. The US study included 30,000 volunteers, 20,000 of whom received the vaccine while the rest received dummy injections. The results were announced on Monday. In a statement, AstraZeneca said its COVID-19 vaccine has a 79% effectiveness rate in preventing symptomatic COVID and is 100% effective in stopping serious illness and hospitalization. Investigators said the vaccine was effective at all ages, including the elderly – something earlier studies in other countries had failed to establish.
The first results of the US study are just a set of information that AstraZeneca must submit to the US Food and Drug Administration. An FDA advisory committee will publicly debate the evidence behind the injections before the agency decides whether or not to allow emergency use of the vaccine.
Although the vaccine is not approved for use in the United States, it plans to send 1.5 million doses of AstraZeneca-Oxford to Canada, possibly as early as this week.
Scientists were awaiting the results of the US study in the hopes that it will clear up some of the confusion about the plans’ effectiveness.
Britain first cleared the vaccine based on partial results from trials in the UK, Brazil and South Africa, which suggested the vaccines were around 70% effective. But those results were clouded by a manufacturing error that led some participants to receive only half a dose on their first shot – a mistake the researchers did not immediately recognize.
WATCH | Tam says the benefits of the AstraZeneca vaccine outweigh the risks:
Then came other questions, about how the vaccine protected the elderly and how long to wait before the second dose. Some European countries, including Germany, France and Belgium, initially denied the photo to older people and only overturned their decisions after new data suggested it offers protection to older people.
Last week, more than a dozen countries, mostly in Europe, temporarily suspended their use of the AstraZeneca vaccine after reporting it was linked to blood clots. On Thursday, the European Medicines Agency concluded after an investigation that the vaccine did not increase the overall risk of blood clots, but could not rule out that it was linked to two very rare types of clots.
Later Thursday, Health Canada issued a statement saying the benefits of the AstraZeneca-Oxford vaccine outweighed the risks.
At a press briefing a day later, Dr Marc Berthiaume, director of the department’s Office of Medical Sciences, echoed the remarks, but noted officials are “actively monitoring” emerging research on the AstraZeneca-Oxford vaccine. and are in contact with their European counterparts.
France, Germany, Italy and other countries then resumed their use of the vaccine on Friday, with senior politicians rolling up their sleeves to show the vaccine was safe.
Experts supported by results
“These results confirm the previous results observed,” said Ann Falsey of the University of Rochester School of Medicine, who helped lead the trial. “It’s exciting to see for the first time similar efficacy results in people over 65. ”
Julian Tang, a virologist at the University of Leicester who was not linked to the study, described it as “good news” for the AstraZeneca vaccine.
“Previous trials in the UK, Brazil and South Africa had a more variable and inconsistent design and it was thought that the US FDA would never approve the use of the AZ vaccine on this basis, but now the trial American clinic has confirmed its effectiveness. vaccine in their own clinical trials, ”he said.
“Although apparently perhaps slightly less effective on paper, the AZ vaccine is much cheaper and much easier to store and transport than the Pfizer and Moderna vaccines currently in use in the United States.”
AstraZeneca said it will continue to analyze the data for submission to the FDA in the coming weeks. He said the data will also soon be published in a peer-reviewed journal.