EU countries could begin rolling out Moderna's COVID-19 vaccine as soon as next week after authorities approved the region's second shot on Wednesday, with more infectious variants of the virus adding extra urgency to inoculation efforts.

Vaccinating the European Union's 450 million people could be crucial to ending a pandemic that has killed almost 1.9 million people globally. Countries are scrambling to contain two variants found in South Africa and Britain that are more transmissible and have driven a surge in infections.

"With the Moderna vaccine, the second one now authorised in the EU, we will have a further 160 million doses. And more vaccines will come," European Commission President Ursula von der Leyen said on Wednesday.