AstraZeneca said on Monday its vaccine for the novel coronavirus, developed along with the University of Oxford, could be around 90 per cent effective under one dosing regimen.
"This vaccine's efficacy and safety confirm that it will be highly effective against COVID-19 and will have an immediate impact on this public health emergency," Pascal Soriot, Astra's chief executive, said in a statement.
British Health Secretary Matt Hancock described as "fantastic news".
"These figures... show that the vaccine in the right dosage can be up to 90 per cent effective," he told Sky News, after an announcement from AstraZeneca.
"We've got 100 million doses on order and should all that go well, the bulk of the rollout will be in the new year."
The British drugmaker's preliminary trial results mark a fresh breakthrough in the fight against a pandemic that has killed nearly 1.4 million people and roiled the global economy.
Russian ballistic missiles killed at least five people and injured over two dozen more in Kyiv early on Thursday, authorities said on the Telegram messaging app, damaging buildings and leaving parts of the Ukrainian capital without power.
South Korea and the United States will cut short annual joint military drills to five days from 11 and scale back some field training, the allies said on Wednesday, after President Donald Trump ordered a substantial reduction in US participation.
At least 100 people were killed when a low-tech artisanal gold mine collapsed in the Central African Republic on Tuesday, a senior official at a local mining association said.
An Israeli airstrike killed nine Palestinians at a police station in Gaza on Wednesday, medics said, two days after US envoy Jared Kushner ended a trip to the region that failed to push forward Donald Trump's plan to end the war in the enclave.