AstraZeneca says U.S. trial data shows its Covid-19 vaccine is 79 percent effective

The news comes after almost a dozen countries restarted administering the vaccine after a pause over fears of serious side-effects.

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LONDON — A vaccine developed by AstraZeneca and Oxford University is highly effective at stopping Covid-19 and completely prevents severe illness and hospitalization across all age groups, the company announced on Monday.

AstraZeneca said it will now apply to the Food and Drug Administration for emergency use authorization and release its data for analysis by the scientific community in peer-reviewed literature.

The Phase 3 trial, conducted in the U.S., Chile and Peru with 32,000 volunteers, showed the vaccine was 79 percent effective against the disease and 100 percent effective in stopping severe and fatal cases, the company said in a news release.

A dose of the AstraZeneca Covid-19 vaccine is administered to a patient in Ede, the Netherlands, on Saturday.Piroschka van de Wouw / AFP - Getty Images

More than 50 countries across the world have approved the AstraZeneca vaccine, developed in partnership with Oxford University, including the United Kingdom, which did so in December and has now vaccinated half its adult population.

But while the vaccine has already repeatedly been shown to be safe and effective in trials, it suffers from a reputation problem. Last week, almost a dozen countries restarted administering the vaccine after a pause over fears of serious side-effects such as blood clots.

The results announced Monday showed an even higher rate of effectiveness than studies conducted in Oxford, the company said.

"These results are great news as they show the remarkable efficacy of the vaccine in a new population and are consistent with the results from Oxford-led trials," said Andrew Pollard, professor of pediatric infection and immunity, and the lead investigator of the Oxford University trial.

"We can expect strong impact against Covid-19 across all ages and for people of all different backgrounds from widespread us of the vaccine."

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Last week, the European Medicines Agency said the vaccine was safe and now AstraZeneca has said it found "no increased risk of thrombosis" among the 21,583 trial participants receiving at least one dose.

Experts have previously warned there is no causal link between the vaccine and blood clots and that even temporarily suspending the vaccine's use could do more harm than good.

Some European countries, including Germany and France, had initially approved the vaccine but recommended against older people receiving it, before making it available to over-65s.

AstraZeneca said Monday that its effectiveness in people aged 65 and over was 80 percent.

Nevertheless, there is now a lower level of trust in the vaccine across Europe compared to the one from Pfizer-BioNTech. Polling company YouGov said people in France, Germany, Spain and Italy are now more likely to consider it unsafe than safe, according to a poll of 8,000 people released Monday.

In France, 61 percent said it was unsafe, while 55 percent of Germans said the same. Only in the U.K., which has been administering the vaccine since January, have concerns over side-effects caused no dip in confidence, with 77 percent believing it to be safe.

Meanwhile, the U.S. has been steadily building a stockpile of some 7 million shots of the vaccine — some of which the Biden administration is sending to Canada and Mexico.

The U.S. has signed a deal to receive 300 million doses of the vaccine, after its approval, and aims to have enough doses for all adults by May.