AstraZeneca vaccine up to 90% effective and easily transportable, company says

By
William Booth and
Antonia Noori Farzan (TWP)

LONDON — AstraZeneca on Monday became the third pharmaceutical company to announce promising results from late-stage trials of a coronavirus vaccine, saying that its candidate, developed by Oxford University, is up to 90 percent effective.
That would make it somewhat less protective than vaccines by Pfizer-BioNTech and Moderna, which each reported 95 percent effectiveness. But the Oxford-AstraZeneca vaccine may be a more realistic option for more of the world, as it is likely to be cheaper and does not need to be stored at subzero temperatures.
The Oxford-AstraZeneca team said in a video conference with journalists that their candidate’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 was at 62 percent. But it rose to 90 percent when a subject received only a half-dose, followed with a full dose one month later.Andrew Pollard, chief investigator of the Oxford 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.
Sarah Gilbert, a lead Oxford researcher, cautioned that this one-two punch would have to be more closely studied to be fully understood. But she said the first half-dose might be priming a person’s immune system just enough, and that the second booster then encourages the body to produce a robust defense against sickness and infection.
Shares in AstraZeneca slipped nearly 3 percent on the London stock exchange by mid-afternoon.
The United States has preordered 300 million doses of the vaccine. Britain has ordered 100 million.
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.
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 somewhat lower efficacy than Pfizer and Moderna, 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.
“I am really very pleased. I really welcome these figures, this data, which shows that the vaccine in the right dosage can be up to 90 percent effective,” Hancock told Sky 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 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.
“We don’t have enough supply for the whole planet,” Pollard said, adding that the important message is that today there are at least three highly effective, safe vaccines, that also appear to work well among the elderly, and that they are produced using different technologies, ensuring the quickest route to manufacture the billions of doses that will be necessary.
Pollard said it is “unclear why” the different vaccines were producing different results, and he said he and the scientific community awaited full data sets from all the clinical trials to fully understand what is going on. He said different studies were also using different end points to describe efficacy.
“At this moment we can’t fully explain the differences,” Pollard said. “It’s critical to understand what everyone is measuring.”
Peter Piot, director of the London School of Hygiene & Tropical Medicine, who was instrumental in the battle against AIDS, said the importance of the announcements about the three vaccine candidates cannot be overestimated.
“The only way to stop covid-19 in its tracks is having multiple effective and safe vaccines that can be deployed all around the world and in vast quantities,” Piot said.