The EU says UK-Swedish drug firm AstraZeneca will now supply an additional nine million Covid vaccine doses by March, after days of criticism of the bloc's vaccination programme.
Commission President Ursula von der Leyen said it was a "step forward".
But the 40m doses now expected are still only about half of what had been hoped, amid continuing supply problems.
The Commission has been involved in a much-criticised row with both the UK and AstraZeneca this week.
In particular it was condemned over its threat to put checks on the Northern Ireland border to prevent vaccines produced in the EU from reaching the UK.
The border was one of the most difficult problems to overcome in the recently agreed Brexit deal, following the UK's departure from the EU.
The EU was angry that Britain was getting its UK-made contracted supplies from AstraZeneca while it suffered a shortfall. So the bloc announced it was introducing export controls on coronavirus vaccines made inside the EU to try to protect its supplies. The Brexit deal ensures there are no obstacles to trade between the Republic of Ireland and Northern Ireland .
What is the EU chief promising?
In a tweet, Ms von der Leyen said AstraZeneca would "deliver 9 million additional doses in the first quarter (40 million in total) compared to last week's offer & will start deliveries one week earlier than scheduled".
She said this represented a 30% increase on the previous amount.
Irish broadcaster RTE is reporting that the country will get another 100,000 doses as a result.
The EU signed a deal in August for 300 million AstraZeneca doses, with an option for 100 million more.
It was hoped 80 million would be delivered in the first quarter of 2021 - although other sources had put the figure at 100 million - but AstraZeneca said there were production problems at its Dutch and Belgian plants. Media reported this would mean a 60% cut in supplies to the end of March.
There followed a terse exchange between the two parties on contractual obligations, the EU arguing it was binding and the drug firm saying it had only to provide its "best reasonable efforts". The contract between the two was partly published as both tried to win the argument.
The Commission pointed out it could be supplied from UK-based plants, but the UK staunchly defended its supply contracts with AstraZeneca.
The UK was the first country to approve the vaccine, on 30 December - the EU only did so on Friday.
The EU, also on Friday, announced its so-called transparency mechanism, which gives countries in the bloc powers to deny authorisation for vaccine exports if the company making them has not honoured existing contracts with the EU.
The EU's attempt to apply measures to the Irish border was widely condemned, and the heads of the UK- and Europe-wide industry bodies warned against export bans.
The EU stepped back and, in a call with Prime Minister Boris Johnson, Ursula Von Der Leyen said that "there will be no disruption of contracts that we have with any producer in the EU".
So what has been achieved?
In addition to her announcement on the doses, Ms Von Der Leyen said she had had a video-conference with vaccine manufacturers.
In an earlier tweet she spoke of "our new initiative to strengthen bio-defence preparedness", adding: "We're discussing how to address Covid-19 variants & scale up manufacturing, be better prepared for future pandemics."
There was no reference to the talk earlier in the week of legal action and "hijacking" of supplies. The BBC's Kevin Connolly says this was a curiously flat and bland conclusion to a week of stormy rhetoric.
The additional doses announcement will be greeted with relief in Brussels, our correspondent says, but it still leaves the European Commission facing awkward questions about how its signing of supply contracts and approval processes have lagged behind those of other wealthy nations.
Even Ms Von Der Leyen's reference to AstraZeneca expanding its production in Europe and the earlier supply date were partly signalled by the firm last week.
But she said on Sunday that the EU was maintaining its "target of vaccinating 70% of adults by the end of summer".
"Our opponent is the virus and the pharmaceutical industry is part of the solution," Ms Von Der Leyen told German public broadcaster ZDF.
Damage done
Remember just how long and difficult the Brexit negotiations were in reaching an agreement on Northern Ireland? Think about how often the EU lectured the UK government about the importance of respecting the detail of the arrangement; how peace in Northern Ireland was at stake.
Yet the impression the European Commission gave on Friday - however incorrect or unintended, which is what it insists - is that those concerns could be thrown aside in a heartbeat.
The European Commission back-tracked late on Friday (although it has reserved the right to revisit the issue, it says, if it sees EU-manufactured vaccines entering the rest of the UK via Northern Ireland).
The U-turn was publicly welcomed by Taoiseach Micheál Martin. But take a look at political and press reaction in Ireland, Northern Ireland and the rest of the UK, and you'll see a lot of damage had already been done.
https://news.google.com/__i/rss/rd/articles/CBMiLmh0dHBzOi8vd3d3LmJiYy5jb20vbmV3cy93b3JsZC1ldXJvcGUtNTU4NzkzNDXSATJodHRwczovL3d3dy5iYmMuY29tL25ld3MvYW1wL3dvcmxkLWV1cm9wZS01NTg3OTM0NQ?oc=5
2021-01-31 23:03:00Z
52781341197483
