The announcement follows upbeat results from two other front-running vaccine candidates, by Pfizer-BioNTech and Moderna, in the last two weeks.
The Oxford-AstraZeneca vaccine is likely to be cheaper than those made by Pfizer and Moderna, and it does not need to be stored at subzero temperatures but can be kept in ordinary refrigerators in pharmacies and doctor’s offices.
AstraZeneca executives said the vaccine is already being manufactured. The first 4 million doses could be ready in December, and 40 million could be delivered in the first quarter of 2021, they said. By the spring, the company and its global partners in India, Brazil, Russia and the United States could be cranking out 100 million to 200 million doses a month.
Andrew Pollard, chief investigator of the Oxford Vaccine Trial, said the findings showed that the vaccine would save many lives.
“Excitingly, we’ve found that one of our dosing regimens may be around 90 percent effective, and if this dosing regimen is used, more people could be vaccinated with planned vaccine supply,” he said.
The Oxford-AstraZeneca team said in a video conference with journalists that the vaccine’s average efficacy was 70 percent, reflecting the disparate results from two different dosing regimens. When two full doses were given at least one month apart, efficacy fell to 62 percent. But it rose to 90 percent when a subject received only a half dose, followed with a full dose one month later.
AstraZeneca and Oxford have been conducting Phase 3 clinical trials worldwide, with the most recent data coming from an interim analysis based on 131 coronavirus infections in Britain and Brazil among 10,000 volunteers, with half getting the vaccine and half getting a placebo.
No participants who received the vaccine developed severe cases or required hospitalization, AstraZeneca said Monday. The drugmaker also said that no “serious safety events” were reported in connection with the vaccine, which was typically “well tolerated” by participants regardless of their dosing levels or ages.
While the results released by AstraZeneca indicate slightly lower efficacy, the vaccine can be stored and transported at normal refrigerated conditions for up to six months. That could make it significantly easier to roll out than Pfizer’s vaccine, which has to be stored at minus-70 degrees Celsius, or Moderna’s, which is stable in refrigerated conditions for only 30 days and must be frozen at minus-20 degrees Celsius after that.
Matt Hancock, Britain’s health secretary, said the Oxford-AstraZeneca vaccine announcement was great news.
Hancock said the British government has already ordered 100 million doses of the vaccine, “and should all that go well, the bulk of the rollout will be in the new year.”
AstraZeneca said it would present the results to Britain’s health-care products regulators immediately. Company executives said they would quickly seek approval to fine-tune their clinical trials in the United States, to experiment with giving volunteers there a first half-dose followed by a booster, which produced the 90 percent efficacy in Britain and Brazil.
The Oxford-AstraZeneca vaccine was first developed in a small laboratory running on a shoestring budget by Sarah Gilbert at Oxford and her team. The university kicked in 1 million pounds ($1.3 million) and then sought a manufacturing partner, before settling on AstraZeneca.
“We wanted to ensure there wouldn’t be any profiteering off the pandemic,” said Louise Richardson, the university’s vice chancellor, so that their vaccine would be widely distributed “and wouldn’t just be for the wealthy and the first world.”
The scientists said that although it appeared to be a race, or a competition, among the front-running vaccine developers, no one company could produce by itself the millions of doses needed to end the pandemic.