The EU's drug regulator approved the Moderna coronavirus jab yesterday, the bloc's second and a shot in the arm for Europe's slow-moving vaccine roll-out. 

In a long-awaited decision, the Amsterdam-based European Medicines Agency (EMA) gave the green light for the US firm's vaccine for use on people over 18.

Criticism has mounted of the EU's sluggish start to its vaccination campaign since the first vaccine, by Pfizer-BioNTech, was authorised in late December.

"This vaccine provides us with another tool to overcome the current emergency," EMA Executive Director Emer Cooke said in a statement.

The EMA's one-year conditional marketing authorisation is for two injections of the Moderna vaccine into the arm, 28 days apart. Moderna's jab was found to be 94.1 percent effective in preventing Covid-19 compared to a placebo in a clinical trial of 30,400 people, performing slightly better in younger adults compared to the elderly.

The Covid-19 crisis has shown no signs of slowing, with known infections nearing 86 million worldwide and more than 1.8 million deaths, even as many nations ramp up their vaccination rollouts.

England began its third national lockdown Tuesday. Denmark and Germany also extended and increased coronavirus measures on Tuesday.

Britain and Denmark have said they will wait for longer than the recommended 21-28 days between jabs so they can focus on giving more people their first dose -- a move that has divided specialists.

But World Health Organization experts on Tuesday gave cautious backing "in exceptional circumstances" to delaying the second doses of the Pfizer-BioNTech vaccine.

In China, schools were shut and travel was restricted in the northern city of Shijiazhuang -- home to around 11 million people -- as authorities moved to snuff out a cluster after dozens were infected.

The United States broke its own record for the number of daily deaths from Covid-19 yet again Tuesday, recording 3,936 fatalities in 24 hours, according to a tally kept by Johns Hopkins University.

The world's worst-hit nation is ultimately counting on its vaccination campaign, which began mid-December, to end the crisis. But less than two percent of the population has so far been covered, with 4.8 million people having received the first of two doses.