"We are continuously revising our delivery schedule and informing the European Commission on a weekly basis of our plans to bring more vaccines to Europe", the AstraZeneca spokesman said in his initial comment. Officials say the Johnson & Johnson vaccine could be approved next month.
The EU official, who is directly involved in talks with the Anglo-Swedish drugmaker, said the company had told the bloc during internal meetings that it "would deliver less than 90 million doses in the second quarter". "But this is a psychological problem, and it will take time to reach its goal". Most of the company chiefs said they expect an improvement in the second quarter.
In March, the bloc could also authorize the Johnson & Johnson one-shot vaccine.
"The big challenge for us in Q2 and Q3 will be the administration of the vaccines, because it will be unprecedented".
"Our teams are absolutely stretched to the maximum. There's no way they could train any more people", he said.
Trials of a single-dose vaccine from US -based Johnson & Johnson have also demonstrated only slightly less effectiveness against the South African variant.
Soriot came under fire after he confirmed that the company would deliver less than half the vaccines it had committed to in the first quarter.
Denmark plans to launch a digital passport to document a traveller's vaccination status, created to be compatible with any future EU-wide scheme.
A nurse administers the Oxford-AstraZeneca COVID-19 vaccine to a member of the medical staff in La Baule, France, February 17, 2021.
Commission President Ursula Von der Leyen said that Google and Apple were already offering their vaccine certificate solutions to the World Health Organization.
However, while hiking up output in the third quarter could be conducive to helping the European Union meet its vaccination targets, the bloc's negotiators were reportedly sceptical.
Dr. Gilbert said Britain made the right decision given the rapid spread of a new variant of the virus that was first detected in Kent, outside London, last November.
And the member states now face outbreaks of more contagious variants from Britain and South Africa. This means that restrictions could well continue through coming months.
"There is growing Covid fatigue among our citizens".
Also debated was the issue of "vaccine certificates", which could help smooth a return to air travel and possibly avoid another disastrous summer holiday season, as the tourism industry and broader economies suffer from restrictions.
Southern European countries that are heavily tourism-dependent, including Greece, are banking on some version of a certificate or "vaccine passport" to allow people to move freely this summer without fears of quarantines or other border restrictions.
As of Thursday, at least 10.17 million people across the European Union have been fully vaccinated with two doses - only 2.3 percent of the population - according to AFP's tally from official sources.
"The most important question remains whether you can still transmit the disease". There are widespread concerns that these could result in discrimination against those who choose not to be vaccinated.
"We are working quite hard on this and trying to convince people to accept the vaccine and really to rebuild the trust in the vaccine in the population", Thomas Mertens, a professor who chairs Germany's Standing Commission on Vaccination, told the BBC on Thursday.