A World Health Organisation chief praised Ireland for its handling of the coronavirus - as he warned it could be 2023 before people can get vaccinated.
Its special envoy on Covid-19, Dr David Nabarro complimented Irish health chiefs and the public for their commitment in fighting the spread of the disease.
However, his welcomed comments came as he gave a grim vaccine timeline.
When asked when he thought one might be available, he said with a sigh: "I wish I could answer that question.
"There are candidate vaccines now all over the world. More than 100 of them.
"And it's absolutely wonderful to see the huge amount of science research being done.
"A vaccine though is not a sort of guarantee that you can develop a product that you hope will enable people to be immune against infection by the virus.
"But then you have to test it to check if immunity applies to everybody and you have to be sure that the vaccine is safe.
"A lot of people are very nervous about vaccination all over the world so safety is paramount.
"Now that testing work takes time and you can't rush it.
"Some manufacturers are saying they are in what we call 'phase three trials' which is great news.
"But I think to have a proven vaccine is still going to take us some months and we won't have one until next year.
"Then the real issue is how you build up the manufacturing capacity and make sure everyone in the world can have it.
"And I think that is two and a half years (away)."
Dr Nabarro told RTE's Morning Ireland he wished every country took the virus more seriously and took quicker action in combating the outbreak.
He raised concerns over the surge in cases in the Americas, India and Africa but commended the work being done in the Republic of Ireland.
He said: "I'm a real fan at what Ireland has done and I've enjoyed interactions with Irish people through the media.
"I must just say yes you've had some challenges but I do sense you've got a pretty clear strategy now.
"And I would say to everybody I want you to encourage you to continue to take this virus seriously and I want everyone in the world to know what I know about it.
"We've all got to learn to keep it at bay."
