U.K. Authorizes Covid-19 Vaccine From Oxford and AstraZeneca

LONDON — Britain on Wednesday became the first country to give emergency authorization to the coronavirus vaccine developed by AstraZeneca and the University of Oxford, clearing the path for a cheap and easy-to-store shot that much of the world will rely on to help end the pandemic.

In a bold departure from prevailing strategies around the world, the British government also decided to begin giving as many people as possible a first dose of coronavirus vaccines, rather than holding back supplies for quick second shots, greatly expanding the number of people who will be inoculated.

That decision put Britain at the vanguard of a far-reaching and uncertain experiment in speeding up vaccinations, one that some scientists believe will curb the suffering wrought by a pandemic that has been killing hundreds of people each day in Britain and thousands more around the world.

The effects of delaying second doses as a way of giving more people the partial protection of a single dose are not fully known. Britain, believed by experts to be the first country to undertake such a plan, will also delay second doses of the Pfizer-BioNTech vaccine, which has been in use there for several weeks and