Key roles range from the World Health Organisation to heading New Zealand's virus response
The Irish have found themselves in the front line of fighting the coronavirus pandemic around the globe.
From the upper echelons of the World Health Organisation and working at the cutting edge of scientific research to develop a vaccine, to devising public health strategies to combat Covid-19 in New Zealand, England and the US, they are among the leading lights working to contain the virus.
Dr Caroline McElnay
Dr McElnay is the director of public health for the New Zealand Ministry of Health and chief adviser to Jacinda Ardern's government on all matters related to the Covid-19 pandemic.
She is the New Zealand government's equivalent of Ireland's chief medical officer Tony Holohan.
Dr McElnay is the daughter of a dairy farmer from Bushmills, Co Antrim.
She studied medicine at Queen's University Belfast and later public health at Manchester University before emigrating to New Zealand 25 years ago.
Now, she is the public face of New Zealand during the coronavirus crisis, appearing daily on TV screens for lengthy briefings on how the administration is winning the battle against the coronavirus. The public health expert has lived in New Zealand since 1995 with her husband and is now a citizen with three children - Caitriona, Roisin and Conor.
Professor Yvonne Doyle
Professor Yvonne Doyle was appointed medical director and director of health protection for Public Health England in 2019.
She is from Dublin and studied medicine in UCD.
She has worked for many years in the NHS in England and has been a leading force in their fight against the coronavirus.
After qualifying in Ireland, Prof Doyle went on to work in senior roles in the NHS and Department of Health and Social Care (DHSC).
The 63-year-old has also worked in the academic and independent sectors.
Between 2016-2019 she was statutory adviser to Boris Johnson, then the Mayor of London.
In 2019 she was appointed medical director and director of health protection for Public Health, England.
She has acted as an adviser to the WHO on healthy cities and continues to take a research interest in urban health and the environment.
Dr Mike Ryan
The Mayo man is executive director of the World Health Organisation's Health Emergencies Programme.
He leads the team responsible for the international containment and treatment of Covid-19.
His measured, calm and at times heartfelt daily briefings are broadcast across the world.
It is a world that has been changed utterly over the past few months by the global pandemic that continues to claim lives and haunt us.
In words that will go down in history, Dr Ryan (55) wisely counselled governments at the outset. "Be fast, have no regrets. You must be the first mover. The virus will always get you if you don't move quickly," he warned. "If you need to be right before you move, you will never win."
Dr Ryan grew up in Charlestown in Co Mayo and later moved down the road about 5km to Curry, Co Sligo.
But both counties proudly lay claim to him.
He studied medicine at the National University of Ireland Galway and later trained as a trauma surgeon.
But that career path ended when, during a 12-week humanitarian trip to Iraq in 1990, he was severely injured when the car he was travelling in was run off the road by a military convoy.
Breaking his back in three places, the horrific accident resulted in the end of his surgical career but the beginning of another. He retrained in public health and epidemiology and has been at the forefront of managing acute risks to global health for nearly 25 years.
Those who know Dr Ryan personally speak of his sincerity, innate good humour, optimism and commitment to the common good.
He is a humanitarian in the true sense of the word.
On the issue of herd immunity, he recently told a press briefing in Geneva: "Humans are not herds. As such, the concept of herd immunity is generally reserved for calculating how many people will need to be vaccinated in the population in order to generate that effect.
"This is a serious disease, this is public enemy number one, we have been saying it over and over and over and over again."
He warned: "No one is safe until everyone is safe", adding: "So I do think this idea that 'maybe countries who had lax measures and haven't done anything will all of a sudden magically reach some herd immunity, and so what if we lose a few old people along the way?' - this is a really dangerous, dangerous calculation.
"Responsible member states will look at all their population - they value every member of society."
Dr Gordon Joyce
Dr Gordon Joyce, from Co Galway, is currently at the forefront of the global scramble to develop an effective vaccine against Covid-19.
Dr Joyce is the head of structural biology at the Walter Reed Army Institute of Research, a US military lab near Washington.
He has been employed by the US military for years and has carried out groundbreaking work on viruses such as influenza and HIV.
The Irish virologist was working on a vaccine for MERS, also a coronavirus, until early this year. However, since the emergence of Covid-19, Dr Joyce and his team have shifted their efforts and expertise to develop a vaccine that could slow the spread of the virus and ultimately end the devastating pandemic.
Born in relative poverty in Knockaderry, Co Limerick, Michael Dowling is the president and CEO of Northwell Health, a healthcare provider that operates 23 hospitals, the largest in New York state.
Mr Dowling was hand-picked by New York state governor Andrew Cuomo to be the crisis manager for the state's coronavirus response.
He commands more than 800 outpatient facilities and 72,000 employees. The governor's inner circle is known to be small, and Mr Dowling is thought to be one of his most trusted lieutenants.
Mr Dowling grew up in a thatched cottage with a mud floor where the only toilet was outside.
He worked hard from a young age to support his family before attending UCC and studying Arts.
He later moved to America, did a Masters in Social Policy at Fordham University and was a rising star on the faculty there when Mr Cuomo invited him to join his administration.