At least 12 of the European Union's 27 member states have said they are confident of being able to vaccinate 70 per cent of their adult population by mid-July, the EU executive's vaccine task force chief said on Tuesday.
European internal market commissioner Thierry Breton told an Irish parliamentary committee that the EU was "confident" it would be able to deliver enough doses.
The European Commission has set a target of inoculating 70 per cent of the EU's adult population by the end of this summer, banking on a big increase in vaccine deliveries to accelerate its vaccination drive.
"We are confident that we will be able to deliver enough doses but it is true also that it is up to member states to organise themselves to be ready for that," Mr Breton told the EU affairs committee.
"Today I can tell you that I understand we have at least 12 member states who say they are fully comfortable this 70 per cent figure. This number is increasing on a daily basis."
Mr Breton did not identify the 12 member states or say which countries were less comfortable with the 70 per cent figure.
An announcement last week that EU countries will receive 50 million more vaccines produced by Pfizer and BioNTech this quarter has given the executive additional comfort on its delivery targets, he added.
It has also provided "room for manoeuvre" to cope with Mr Breton's expectation that the bloc will initially have fewer Johnson & Johnson shots than hoped.
He said he was also confident AstraZeneca will be able to deliver its reduced second quarter target of 70 million vaccines.
Mr Breton, who expressed hope recently that Europe will have a summer tourist season this year, said the vaccine target was important to provide "light at the end of the tunnel" before the holiday season.