LONDON--AstraZeneca said on Monday its COVID-19 vaccine was 70% effective in pivotal trials and could be up to 90% effective, giving the world's fight against the global pandemic a third new weapon that can be cheaper to make, easier to distribute and faster to scale-up than rivals.
The British drugmaker said it will have as many as 200 million doses by the end of 2020, around four times as many as U.S. competitor Pfizer Inc. Seven hundred million doses could be ready globally as soon as the end of the first quarter of 2021.
"This means we have a vaccine for the world," said Andrew Pollard, director of the Oxford University vaccine group that developed the drug.
The vaccine on average prevented 70% of COVID-19 cases in late-stage trials in Britain and Brazil. The success rate rose to 90% in a group of trial participants who accidentally received a half dose followed by a full dose. The efficacy was 62% if the full dose was given twice, as it was for most study participants.
No serious safety events were confirmed, the company said, although little safety data was provided.
AstraZeneca's shares fell nearly 4%, as investors perceived the efficacy data as less impressive than rival vaccines and may take longer to get U.S regulatory approval. Pfizer and Moderna , which reported that their vaccines were about 95% effective in preventing illness, had set the success bar sky-high.
The AstraZeneca vaccine does have advantages. Its cost to governments works out at just a few dollars a shot, a fraction of the price of the Pfizer and Moderna vaccines using a new, more complex technology.
It can also be transported and stored at normal fridge temperatures, which proponents say would make it easier to distribute - especially in poor countries - than Pfizer's, which needs to be shipped and stored at -70C.
The 90% efficacy finding was a happy accident, AstraZeneca admitted, noting that it resulted from a dosing error during the trials. The half dose-first regimen will enable the company to seek approval based on far higher effectiveness than 62%, which was still enough for a regulatory nod based on prior discussions.
AstraZeneca Chief Executive Pascal Soriot said the smaller initial dose means limited supplies could stretch even further to vaccinate more people.
The faster roll-out means countries that had been drawing up plans to ration vaccines can distribute them more widely, helping to eventually halt the social and economic disruption of a pandemic that has killed 1.4 million people. "Vaccines are now edging ever closer to liberating us from the virus, demonstrating emphatically that this is not a pandemic without end," Britain Prime Minister Boris Johnson told parliament on Monday.
Matt Hancock, health secretary of Britain which has pre-ordered 100 million doses for its 67 million people, said the bulk of the vaccine rollout will take place January-March. "We hope that sometime after Easter things will be able to start to get back to normal," he said.
