'Difficult weeks' ahead, as variants spread across EU

"[But] we do have the means, we have the resources, we have the capability to succeed over the next few months," he added.

More than 50 million doses have so far been delivered to EU member states, which have administered 29 million jabs (almost seven percent of the bloc's population), according to the European Commission.

The EU vaccine strategy has come under fire over the slow pace of immunisation programmes in member states, compared to the UK, the US, or Israel.

Brussels aims to vaccinate at least 70 percent of its adult population by the end of September, but has struggled to receive the doses agreed with pharmaceutical companies.

Following recent delivery delays, EU leaders stressed that predictability was crucial to organising national inoculation programmes, urging vaccine-developers to respect contractual deadlines.

Meanwhile, the president of the commission, Ursula von der Leyen, said that Moderna and Pfizer/BioNtech were honouring their commitments, while AstraZeneca had "some room for improvement."

She warned the Anglo-Swedish company that the EU executive "will keep a very close eye at what is happening" with their vaccine exports to third countries.

AstraZeneca boss Pascal Soriot said on Thursday that he hoped to meet the EU's expectations for the second quarter - when 180 million doses are supposed to be delivered.

"We are working 24/7 to improve delivery and hopefully catch up to the expectations for Q2," Soriot told EU lawmakers in a grilling the same day as the video-summit, arguing that lower-than-expected yields had slowed down production.

He also confirmed AstraZeneca was trying to supply 40 million doses to the EU by the end of March - which is less than half the amount promised in the contract.

The EU expects to receive a total of 100 million doses in the first quarter, reaching 600 million doses in the second quarter, and over 1 billion doses in the third quarter.

Non-essential travel restricted

Although 20 member states are experiencing stable or decreasing infection rates, there are major concerns about recent spikes in regions where the British variant has become more dominant.

EU leaders pointed out the need to detect and fight new variants, develop new adapted vaccines, and speed up their approval and production, welcoming the commission's new programme to control new mutations.

Just a few hours before, the European Medicines Agency presented its guidelines on accelerating the approval of vaccines adapted to new variants.

"The epidemiological situation remains serious, and the new variants pose additional challenges," EU leaders said in a statement, which also warned that that tight restrictions should be maintained and travel must be curbed.

Member states also committed to ensuring the good functioning of the single market, taking into account the specific situation of cross-border communities.

Earlier this week, the commission wrote to Germany, Belgium, Hungary, Finland, Denmark, and Sweden, saying their border restrictions had "gone too far".

Three months for vaccine certificates

EU leaders also agreed to continue working on certificates for those vaccinated against Covid-19, although the commission has warned that it might take up to three months to make their systems interoperable.

EU countries recently agreed on the minimum dataset needed for such certificates, including the holder's national-ID number, the type of vaccine used, or the number of doses received.

The purpose of these certificates will be decided by member states, but "it is important to have an EU solution," said von der Leyen, warning that there are still some political and scientific questions unanswered.

For example, it is still unclear if you can transmit the disease even after being vaccinated.

Greece and industry players like the International Air Transport Association are pushing to use this document to facilitate travel across the bloc - an idea supported by other tourism-dependent countries such as Cyprus, Spain, Malta, Portugal, and Italy.

"The certificate will not be equivalent to a health passport, but instead will open a fast lane for travel, without the restrictions caused by diagnostic tests and mandatory quarantine," said Greek prime minister Kyriakos Mitsotakis.

However, France and Germany, among others, are against the idea of Covid-19 passports, fearing it would feed anxiety among citizens, and discriminate against those who cannot or will not take a shot.

Greece and Israel signed an agreement last week on a "green passport" that allows citizens vaccinated against Covid-19 to travel without restrictions, and Cyprus intends to clinch the same deal soon.

Sweden and Denmark have also announced plans to introduce a similar document.

Additionally, EU leaders pledged to share more vaccines with third countries, notably with Africa and neighbouring countries, through the World Health Organisation-led Covax program - as worldwide coronavirus deaths topped 2.5 million.