Britain grants emergency approval to coronavirus vaccine by Oxford and AstraZeneca

Researchers from the Oxford-AstraZeneca team earlier this month published interim results that showed their vaccine was 62 percent effective for volunteers who were given two full doses and 90 percent effective for a smaller subgroup who received a half dose followed by a full dose.

Doubts have been raised over how robust the half-dose data is. The Oxford scientists said they were studying why the different regimens produced such different results.

At a briefing by Britain’s Medicines and Healthcare products Regulatory Agency (MHRA), which approved the vaccine, independent scientists said the data provided by Oxford-AstraZeneca, from clinical trials in Britain, Brazil and South Africa, showed the vaccine was “around 70 percent” effective.

The regulators essentially discounted the claim of 90 percent efficacy, concluding the results of the half-dose regimen could not be supported right now.

They authorized the vaccine for two full doses.

June Raine, chief executive of British regulator, said “no corners were cut” in the rapid review of the new vaccine, even though it was developed at Oxford and backed by the British government. Raine said it has “the potential to save many lives.”

British scientists hailed the approval as tremendous news and added that the Oxford-AstraZeneca could help protect not only Britons but many in the developing world.

Britain earlier this month approved the coronavirus vaccine from pharmaceutical giant Pfizer and the German company BioNTech, becoming the first Western country to authorize mass inoculations. The Pfizer vaccine is 95 percent effective.

Britain badly needs a second vaccine to meet its ambitious goal to inoculate most of the country’s population by the spring.

With a new variant of the virus spreading rapidly, and two-thirds of Britain now in near-lockdown, the new government goal is to inject as many people as possible, as quickly as possible, with the first dose of the AstraZeneca vaccine. A second dose will be given later, within three months. The idea is that the first dose provides enough protection to warrant waiting longer than the usual 21 days between shots.

“In the data, the scientists and the regulators have found the immunity comes from around two weeks after the first dose, and then the second dose should be taken up to 12 weeks later to give you that long-term protection,” Hancock said.

“This means we can spend the first three months vaccinating people with the first doses, getting them that immunity, getting people protection quicker than we possibly could have done otherwise,” he said.

Hancock said having the Pfizer and AstraZeneca vaccines means the government now has “a very high degree of confidence that we can be out of this by spring.”

The United Kingdom has injected some 600,000 people with the Pfizer vaccine, but experts say the government must ramp up quickly, to inoculate 2 million people a week — 10 times the current rate — if it wants to beat back the pandemic quickly.

Britain bet the house on the AstraZeneca vaccine, ordering 100 million doses, compared to 40 million doses of the Pfizer vaccine and 7 million doses of Moderna, which has not been approved in the U.K. yet.

AstraZeneca says it can deliver 40 million doses by the end of March, with a million doses arriving almost immediately. The company has manufacturing facilities in Britain.

Officials said Britain will start inoculating people with the AstraZeneca vaccine on Monday, with residents of nursing homes, health-care workers and people over 80 at the front of the line. There are plans to deliver the vaccine in mass immunization centers, such as sporting arenas and convention halls. 

The AstraZeneca vaccine uses a harmless cold virus that typically infects chimpanzees to deliver to the body’s cells the genetic code of the spike protein that dots the outside of the coronavirus. That teaches the body’s immune system to block the real virus.

There remains some imprecision over exactly how effective the vaccine is — and studies are ongoing.

At a briefing announcing the approval of the vaccine, Wei Shen Lim, a respiratory physician and chairman of the Joint Committee on Vaccination and Immuniztion, said, “The data shared with us, and I am not sure it is entirely in the public domain, calculated the vaccine efficacy between day 22 of dose 1 to the time of dose 2 being given, the figure is around 70 percent.

Lim added, “but I don’t think I should be revealing any more than that at this point in time.”

In an AstraZeneca news release on Wednesday, the company said “the primary efficacy endpoint based on a pooled analysis showed that the vaccine was 70.4 percent.”

AstraZeneca is running an additional clinical trial in the United States, with the goal of enrolling 30,000 participants. If the vaccines prove safe and effective there, Moncef Slaoui, the head of the White House Operation Warp Speed, said it could be granted emergency approval in February or March.

“Today is an important day for millions of people in the U.K. who will get access to this new vaccine,” said Pascal Soriot, chief executive of AstraZeneca. “It has been shown to be effective, well-tolerated, simple to administer and is supplied by AstraZeneca at no profit.”

Soriot told BBC Radio that his company can deliver 2 million doses a week and that the vaccine produces a “good level of protection” after the first of two doses.

If Britain gives the second dose two to three months after the first, “that enables us to protect many more people,” Soriot said.

He said scientists believe the AstraZeneca vaccine will be effective against the new variant detected in Britain.

Public health officials say there is much to recommend the new vaccine, as it costs as little as $3 a dose, is relatively easy to manufacture at huge scale and does not require special handling or deep freezers to store or transport.

The Pfizer vaccine is 95 percent effective but requires special handling and must be kept in special freezers and dry ice at extremely low temperatures.

The health secretary conceded that the need to keep the Pfizer-BioNTech vaccine in special freezers has “made it more challenging to get out, especially to some of the smaller care homes, and those limitations aren’t there for this Oxford-AstraZeneca vaccine.”

Prime Minister Boris Johnson said the approval of the new vaccine was “truly fantastic news — and a triumph for British science,” adding that “we will now move to vaccinate as many people as quickly as possible.”

The news comes amid a spike in coronavirus cases driven by the new variant of the virus, which appears to be 50 percent more transmissible. British hospitals currently have more coronavirus patients than they did when the first wave gripped the country in April.

Britain recorded more than 53,000 cases on Tuesday — the highest in a single day. Over 40 percent of the population is living under the highest tier of restrictions.

Andrew Pollard, director of the Oxford Vaccine Group, told the BBC that the pandemic this year was “like being in a blizzard.”

“We’ve been really struggling uphill through snow drifts with this icy wind in our faces, and I think this morning we do have some respite with this good news and the warmth that that brings,” he said.