Coronavirus: EU sues AstraZeneca over vaccine delivery delays

In a statement responding to the announcement, AstraZeneca said it had "fully complied" with its agreement with the EU, and hoped to resolve the dispute as soon as possible.

"Following an unprecedented year of scientific discovery, very complex negotiations, and manufacturing challenges, our company is about to deliver almost 50m doses to European countries by the end of April, in line with our forecast," the British-Swedish company said.

"We are making progress addressing the technical challenges and our output is improving, but the production cycle of a vaccine is very long which means these improvements take time to result in increased finished vaccine doses," the statement read.

AstraZeneca had previously said that the contract obliged the company to make its "best effort" to meet EU demand, without compelling it to stick to a specific timetable.

UK Prime Minister Boris Johnson's spokesman told reporters he was unaware of the specifics around the legal action. He said AstraZeneca had been a "hugely strong partner for the UK and in fact, globally, for the work they're doing".

Under the contract, any legal action would need to be resolved by Belgian courts.

The EU originally planned to use AstraZeneca as the main vaccine in its rollout, but following the supply issues, the bloc now relies mostly on the Pfizer-BioNTech jab.

Despite vaccine delays, the EU is still aiming for "a minimum of 70% of the entire adult population" to have received at least one dose of a coronavirus vaccine by this summer.

The announcement of legal action on Monday came as some countries began to ease restrictions.

Millions of French children returned to the classroom, as primary schools and nurseries reopened following a three-week shutdown. In Italy, restaurants and bars in much of the country were allowed to serve customers outside, while hairdressers in Belgium reopened their doors.

Meanwhile, the mayor of the Spanish city of Pamplona announced that the annual Sanfermín fiesta in July - with its famous running of the bulls - would be cancelled for a second year.

Outside of the EU, Turkey announced a coronavirus lockdown until 17 May in a bid to curb a surge in coronavirus cases and deaths.