The World Health Organisation (WHO) has made a direct appeal to Ireland not to give COVID 'booster' shots to the general population.
Its Special Envoy on COVID-19, Dr David Nabarro, says countries like Ireland would be taking vaccines away from poor countries if such a programme went ahead.
Health Minister Stephen Donnelly has previously said a COVID-19 vaccine booster programme could get underway as soon as September.
But Dr Nabarro told The Hard Shoulder Ireland should lead by example, with hopes that other countries will follow.
"Last year, at the request of all nations, the World Health Organisation set up a really good system for getting vaccines fairly to the poorer countries of the world.
"It wasn't charity, it was just the system that the rich countries asked us to create - and it could work really well.
"But it goes wrong if rich countries panic and start buying extra vaccines so they can do booster shots or double booster shots.
"So if rich countries are just buying all the vaccine and storing it up for boosters this winter, that actually is taking the vaccine away from the poor countries.
"So the real thing that we want rich countries to do is just not to do booster shots - not now and not for a few months - until poor countries have been able to get a vaccine.
"And in our view, there's no evidence that booster shots are necessary".
Ireland 'a hugely respected country'
And Dr Nabarro says he hopes Britain will also hear his plea.
"I'm also having the same position as the people who run the World Health Organisation, the director-general said 'Please don't do booster shots' and I think we really want to say it out loud.
"We say it to Ireland, because you're on the United Nations Security Council, you're a hugely respected country by nations all over the world.
"If Ireland can stand up and say 'We don't think there's a case for our people to be given booster shots, at least not now', then perhaps other countries will listen.
"Perhaps even your neighbour next door might listen, who knows, because they need to also shift their policies."
Virus 'is going to stay'
On the virus, he says it is here to stay.
"This ain't over, no way - we're still in the midst of a ferocious pandemic.
"We may not read about it so much in the news, because it's not causing such a lot of suffering in the towns and cities of Ireland or the United Kingdom.
"But it's picking up like anything in the United States, and it's terrible in some of the developing countries right now.
"So I want to say to everybody: This is still ferocious and difficult, there are variants still emerging and it is absolutely not done and dusted.
"Actually I think this virus is going to stay, and we as humanity will work out how to live with it - just as we had to do some decades ago with the virus that causes AIDS".
It comes as the Irish Kidney Association says the immuno-compromised population should be 'front and centre' in any queue for vaccine booster shots.
Colin White, national advocacy and projects manager, told Newstalk on Monday: "We are arguing that when the queue starts that we should be there, front and centre.
"We made a very strong case for the prioritisation of the immune-compromised for the initial vaccine rollout, and they got bumped up considerably up the list because the evidence was there that they were clinically extremely vulnerable."
Asked about those who may be immuno-compromised, Dr Nabarro admits some people will need extra shots.
"I wouldn't call it a booster shot - that's the shot that is indicated by the clinical condition of the patient.
"And yes: there are people who are at high-risk in Ireland or in other advanced countries... but that's not booster shots.
"That's particular indications - I'm talking about a decision by a country to offer all people over a particular age a booster shot or a winter shot, or whatever it's going to be called.
"Personally I don't think that it's warranted on the basis of the evidence we have".