Nine days later, David Quigley arrived home to Dublin from Perth, Australia alongside 100 other young Irish doctors who cut short their training abroad to answer Harris' call to help slow the spread that has infected more than 3,000 people in Ireland.
Quigley, a 30-year-old respiratory specialist, was due to return to a job in Dublin in July after doing some traveling. Amid the travel chaos and canceled flights, he instead forked out 7,000 Australian dollars from his savings to get back early.
"I wanted to come back and help out my colleagues who I had worked with for so long before, to help the cause," Quigley said in a telephone interview from his parents' house in Dublin where he must self-isolate for two weeks.
From the United States to Vietnam and across Europe, overrun health services are helping retirees reactivate licenses, fast tracking student doctors and nurses and looking for help wherever they can find it.
Authorities in Britain put out a plea for 250,000 volunteers to help the health service transport patients, deliver medicine and stay in contact with the most vulnerable in society. They said on Monday the number of volunteers had reached 750,000.
Another 20,000 health professionals who had either retired or left the industry have return following the passing of emergency legislation.
In Spain, which became the third country to report more than 100,000 cases on Wednesday as the death toll rose above 9,000, officials called upon all retired medical professionals under the age of 70, who were still able to work, to join the effort.
For 63-year-old Loles Andolz, returning to the Barcelona hospital she retired from earlier this year means living apart from her husband, who is over 70, and mother, who recently went blind and must live in isolation to avoid infection.
"My grandmother is having a hard time with her daughter's decision, she cries all day long and wonders why she has to go volunteer instead of younger people," Andolz's daughter, Sonia, told Reuters.
"My mother says that she feels like she is going to war and abandoning her family, although she does it gladly."
Ireland's Health Service Executive said it had spoken to thousands of health care professionals who may be eligible to return after it received more than 70,000 responses for its 'Be on call for Ireland' initiative.
Chris Luke, a 61-year old emergency physician, is back in work in the southern city of Cork 18 months after he retired early because of a neck injury and nerve problems in his hand.
"I have no less a degree of trepidation than any other grey-haired emergency physician. But I am glad to be back. I feel I have a purpose," said Luke, working alongside two other consultants who have come out of retirement
Other volunteers like Colm O'Moráin, one of Ireland's leading academic physicians, must wait before being called up. Aged 72, he is "cocooning," a government order that everyone over 70 must stay at home until at least April 12.
O'Moráin, whose son Neil is a doctor on the frontline in a Dublin hospital, sees the opportunity to look after patients in whatever guise as a chance to give back when the need "has never been greater."
While trying to avoid contact with his own parents who are living in a separate part of their house, Quigley, the returnee from Australia, is itching to get started."It's almost harder psychologically to sit back, especially when you're in isolation in your room. As soon as it's safe, I'm definitely, definitely eager to get back working on the frontline," he said.