LONDON – The UK on Wednesday became the first country to approve the emergency coronavirus vaccine developed by AstraZeneca and Oxford University, clearing the way for a cheap and easy-to-store shot that much of the world will rely on to help the pandemic.
In a bold departure from prevailing global strategies, the UK government also decided to give as many people as possible a first dose of coronavirus vaccines rather than holding back supplies for quick second shots, significantly increasing the number of people vaccinated.
That decision has put Britain at the forefront of a far-reaching and unsafe experiment to speed up vaccination that some scientists believe will contain the suffering of a pandemic that kills hundreds of people in the UK and thousands around the world every day.
The effects of delaying the second dose to allow more people to receive partial protection from a single dose are not fully known. The UK, viewed by experts as the first country to implement such a plan, will also delay the second dose of the Pfizer BioNTech vaccine, which has been used there for several weeks and is in clinical trials after a single dose.
Some participants in the Oxford AstraZeneca vaccine clinical trial received the two doses several months apart. UK regulators said Wednesday that the first dose of the vaccine had 70 percent effectiveness against Covid-19 between the time that shot was taken and a second shot was administered, although those numbers apply to a limited subset of study participants, and so do also done have not been published.
Together, the UK’s two steps – getting the Oxford-AstraZeneca vaccine approved and extending the dose gap – provided the clearest signal yet of how countries still infected with the virus could speed up the pace of vaccination programs.
The Oxford-AstraZeneca shot is expected to be the world’s dominant form of vaccination. At $ 3 to $ 4 per dose, this is a fraction of the cost of some other vaccines. It can also be shipped and stored in regular refrigerators for six months instead of the ultra-cold freezers required for Pfizer-BioNTech and Moderna vaccines. This makes it easier to administer to people in poorer and hard-to-reach parts of the world.
“This is very good news for the world – it greatly facilitates the global approach to a global pandemic,” said Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine. Regarding the decision to postpone the second dose, he said, “In a pandemic, it is better to provide some level of protection to more people than that all people who are vaccinated have full protection.”
Instead of giving the two shots of the coronavirus vaccines within a month as originally planned, clinicians in the UK will wait up to 12 weeks to give people a second dose, the government said. Matt Hancock, the health secretary, said people would get the AstraZeneca vaccine early next week.
For the UK, where hospitals are overwhelmed by cases of a new, contagious variant of the virus, the drug agency’s decision offered hope of redress. Healthcare is preparing to vaccinate almost a million people a week in makeshift locations in soccer stadiums and racetracks.
At two full-strength doses, AstraZeneca’s vaccine showed 62 percent effectiveness in clinical trials – significantly less than Pfizer and Moderna’s roughly 95 percent effectiveness. For reasons scientists don’t yet understand, AstraZeneca’s vaccine showed 90 percent effectiveness in a smaller group of volunteers given a starting dose of half strength.
UK regulators approved the vaccine in two full strength doses, saying the other regime’s more promising results were not confirmed by a full analysis. They warned that the promising results for efficacy after a single dose of the vaccine were only true in a limited number of study participants.
Updated
Dec. 30, 2020, 7:16 am ET
In the past few days, the Oxford scientists who developed the vaccine have expressed some support for delaying the second dose. Andrew Pollard, the director of the Oxford Vaccine Group, said in a radio interview Monday that it “makes a lot of sense to start with as many people as possible” by delaying the second dose.
The UK healthcare sector now needs to figure out how to get people to take a vaccine that appears less effective than other vaccines available, but which could hasten the end of the pandemic.
The approval was based on data from late-stage clinical trials in the UK and Brazil. The Indian Medicines Agency is also expected to soon decide whether to approve the vaccine, which is made there by a local vaccine manufacturer, the Serum Institute.
In the US, where the Food and Drug Administration is waiting for data from a separate clinical trial, a decision is further away. The study was canceled in September and delayed by nearly seven weeks – much longer than other countries – when regulators looked at whether a vaccine-related disease in a participant in the UK was carried out. The American regulators ultimately allowed the process.
AstraZeneca has more ambitious manufacturing goals than other vaccine manufacturers and expects to manufacture up to three billion doses over the next year. With two doses per person, this would be enough to vaccinate almost one in five people worldwide. The company has committed to offering it worldwide at cost until at least July 2021 and in poorer countries on a permanent basis.
However, the company has also been haunted by communication errors that have damaged its relationship with U.S. regulators and cast doubt on whether the vaccine will stand up to intense public and scientific scrutiny. These mistakes have shifted the vaccine timeline in the United States, where key FDA officials were baffled when they learned about the break in their clinical trials in September from the news media rather than AstraZeneca.
These setbacks have not dampened the UK craze for the country’s leading homegrown vaccine. According to analysts, this could correct the course of Prime Minister Boris Johnson’s career if introduced quickly.
The UK has made AstraZeneca the linchpin of its vaccination strategy by ordering 100 million doses, 40 million of which should be available by March. The UK has vaccinated hundreds of thousands of people since the Pfizer vaccine was approved on December 2nd. However, the country has struggled to manage it beyond hospitals and doctor’s offices, and some of its highest priority recipients, like nursing home residents, are still at risk.
“We think we’ve figured out the formula for success and figured out how to get the effectiveness that everyone else has after two doses,” Pascal Soriot, managing director of AstraZeneca, told The Times of London in an interview published on Saturday. The company has not released any evidence of efficacy rates as high as Pfizer or Moderna. “I can’t tell you more because we will eventually publish,” Soriot told the Times.
Oxford scientists published interim results from clinical trials of the vaccine in The Lancet this month. The upcoming final results of these studies are not expected to differ significantly from the interim data, as is typical in clinical research.
AstraZeneca’s US study had more than 27,000 enrolled participants last week, which was just below the target of 30,000. The study could have results and, if positive, lead to an emergency clearance in the US in February or March, Moncef Slaoui, head of Operation Warp Speed, the US federal effort to expedite coronavirus vaccines, said in a news conference last week.
