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 Jan. 6, with more infectious variants of the virus adding extra urgency to inoculation efforts.

The EU campaign to vaccinate Europeans against Covid-19 got off to an uneven start in what will be a marathon effort to administer shots to enough of the bloc’s 450 million people to defeat the viral pandemic.

Europe launched a mass Covid-19 vaccination drive on Dec. 27 with pensioners and medics lining up to get the first shots to see off a pandemic that has crippled economies and claimed more than 1.7 million lives worldwide.

The first days of Pfizer Inc.’s Covid-19 vaccine rollout have seen unexpected hitches including some vaccines being stored at excessively cold temperatures and Pfizer reporting potential challenges in vaccine production, U.S. officials said.

Daily U.S. deaths from Covid-19 surpassed 3,000 for the third time in a week as the country expanded its vaccination program and Congress progressed toward approving financial relief for pandemic-stricken America.

The first shipments of Covid-19 vaccine left on trucks and planes early on Dec. 13, kicking off a historic effort to stop a surging pandemic that is claiming more than 2,400 lives a day in the United States.

A 90-year-old grandmother became the world’s first person to receive a fully tested Covid-19 shot on Dec. 8, as Britain began mass-vaccinating its people in a global drive that poses one of the biggest logistical challenges in peacetime history.