In another positive finding, the Oxford vaccine needs only to be refrigerated, unlike other candidates developed by drug companies Pfizer and Moderna, which must be kept at extremely cold temperatures.
Refrigeration will make it easier to transport and store globally, particularly in lower and middle-income countries. The Oxford candidate is also much cheaper.
“We have a vaccine for the world,” said Professor Andrew Pollard, the trial’s lead investigator.
“Our goal at the beginning was to make sure that we can have a vaccine that was accessible everywhere. I think we have actually managed to do that, so it’s a very exciting day today.
“This is an incredibly exciting moment for human health.”
The preliminary results show the Oxford vaccine is 62 per cent effective when delivered in two full doses and up to 90 per cent effective when administered at a half-dose and then a full dose – giving the vaccine an overall average effectiveness of 70.4 per cent.
“Seventy per cent is better than the flu vaccine is in most years,” Pollard said.
Explaining why the half-dose followed by full dose regime produced a better level of protection, Pollard said: “We think that by giving a smaller first dose we are priming the immune system differently, we are setting it up better to respond.”
Pollard said it was too early to know how long coronavirus vaccines protected the recipient and whether the vaccine would have to be rolled out regularly, similar to a flu shot.
Asked about how long the shield may last, Professor Sarah Gilbert, the Oxford vaccine’s architect, said researchers were optimistic an immune response would last “at least a year”.
Qantas chief executive officer Alan Joyce on Monday night said vaccination would be mandatory for passengers.
“We are looking at changing our terms and conditions to say that for international travellers, we will ask people to have a vaccination before they can get on the aircraft,” he said.
“Whether you need that domestically, we will have to see with COVID-19 and the market but certainly for international visitors coming out [to Australia] and leaving, we think that’s a necessity.”
The AstraZeneca vaccine uses a modified version of a chimpanzee common cold virus to deliver instructions to cells to fight the target virus, which is different than the new technology known as messenger RNA (mRNA) deployed by Pfizer and Moderna.
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Moderna and Pfizer have claimed their vaccines have an efficacy of up to 95 per cent.
The Oxford team on Monday said the huge international race to develop a vaccine was not a competition. The scale and pace of the effort needed meant multiple vaccines would be required, they said.
The Oxford trial featured some 24,000 volunteers. The 90 per cent efficacy figure was discovered in a sub-group of more than 3000 participants given the initial half-dose, followed by a full dose at least one month later.
AstraZeneca’s executive vice-president for operations, Pam Cheng, said the company planned to begin supplying doses by the end of 2020.
“We will have approaching 200 million doses by the end of 2020 and more than 700 million doses by the end of [the first quarter] of 2021 globally,” she said.
Australian Health Minister Greg Hunt spoke with AstraZeneca’s Australian chief executive on Monday night and was told the company would seek local regulatory approval “in the coming weeks, if not sooner”.
“Subject to approval, this means that Australians are very much on track for first vaccines in March,” Hunt said.
Oxford also revealed on Monday that early trial data suggested the vaccine had helped reduce asymptomatic infections. This could prove crucial because no vaccine had yet been proven capable of blocking transmission of the disease on top of preventing illness in a patient.
“That’s really going to make a big difference to transmission, so it’s good news all around,” Gilbert said.
AstraZeneca– one of the UK’s most valuable listed entities – will now lodge the trial data with authorities around the world to gain conditional or early approval.
It will also seek an emergency use listing from the World Health Organisation to speed up availability in low-income countries.
Bevan Shields is the Europe correspondent for The Sydney Morning Herald and The Age.
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