"I'm ­immensely proud of my ­Donegal roots,” said Professor William Campbell, the 85-year old Irish scientist awarded a Nobel prize in Medicine yesterday to honor his work in discovering a drug now used to treat 25 million people a year in fighting infections caused by roundworm parasites.

“I'm a Donegal boy and proud to be a Ramelton boy. It was a great place to grow up and was a great start to life.”

On Monday morning at the Karolinska Institutet, Sweden, the Nobel Assembly announced that Campbell would share the 2015 Nobel Prize in Physiology or Medicine with two other scientists for their work in using modern laboratory techniques to discover antiparasitic drugs that have for a long time been hidden in natural herbs and in various soils.

Campbell will jointly share the award with his colleague Professor Satoshi Omura for the discovery of the drug Ivermectin that has drastically lowered incidences of river blindness and lymphatic filariasis by fighting infections caused by roundworm parasites.

A graduate of Trinity College and a current research fellow emeritus at Drew University in New Jersey, Professor Campbell is always proud to tell people about his Donegal roots, despite media in the US completely claiming him as their own.

"I begin every lecture by showing a picture of The Mall in Ramelton [Co. Donegal] and then a ­picture of cows on The Mall, my ­father's cows, and students always ask about it,” Campbell told The Irish Independent.

“Of course it has absolutely nothing to do with the lecture, but I like to tell people where I'm from because it is such a part of me."

The Professor’s family are just as proud of the Donegal-born Nobel prize winner with his older brother Bert, aged 88 and who still lives in Donegal, joking that he “got all the family brains”.

The Campbell family were homeschooled in Ramelton, Co. Donegal after their father had what Bert describes as a “run-in” with the principal of the local school. Their father hired a teacher to teach them at home before they were each enrolled in Campbell College, a boarding school in Belfast.

"We are so proud of Bill and it was wonderful talking on the phone to him about it. His work has made life-changing differences to so many people around the world," Bert said.

Campbell revealed he was shocked when he was first told the news yesterday morning and that he initially thought someone was playing a practical joke on him when he was awoken by a journalist ringing to look for an interview about his great achievement, the first time he was to hear he was a Nobel Laureate.

“When I asked how I could find out, the reporter suggested the website,” he said. .

“I was a bit shocked to be honest. It's a great thrill and I'm delighted for everyone involved in this research.”

Campbell and his colleague Dr. Omura of Japan will share one half of the $960,000 prize while the second half will go to Tu Youyou of China who used traditional Chinese medicine to discover Artemisinin, a drug that has significantly reduced the mortality rates for patients suffering from malaria.

“These two discoveries have provided humankind with powerful new means to combat these debilitating diseases that affect hundreds of millions of people annually,” the Nobel Committee said in a statement.

“The consequences in terms of improved human health and reduced suffering are immeasurable.”

Up to a third of the world’s population are estimated to live in danger of the parasitic diseases that these two drugs prevent, the New York Times reports, meaning that both Ivermectin and Artemisinin are listed as essential medicines by the Word Health Organization.

Born in Donegal in 1930, Dr Campbell graduated with first class honors from Trinity College Dublin with an undergraduate degree in zoology in 1952 and received a PhD from University of Wisconsin, Madison, WI in 1957.

In June 2012 he was awarded an honorary doctorate from Trinity College in recognition for his scientific research and contribution to society. His current work at Drew College sees him overseeing the research work of undergraduate students.

Provost of Trinity College Dublin, Patrick Prendergast, welcomed the announcement stating that “Professor Campbell was centrally involved in developing the cure against river blindness.”

“In 1987 he spearheaded the decision by Merck to distribute that cure free to millions of people in what became one of the first and foremost examples of a public/private partnership in international health. Annually 25 million people are treated under this scheme preventing new cases of river blindness.”

He is the third graduate of Trinity College Dublin to receive a Nobel Prize joining E.T.S. Walton, the physicist who first successfully split the atom, and Samuel Beckett who won a Nobel Prize in Literature in 1969.

The winner of the 2014 Nobel Prize in Medicine also shared an Irish connection. Son of Irish immigrants from Co. Cork, New-York-born John O’Keefe is a British based neuroscientist who was awarded the Nobel Prize for his discovery of place cells in the hippocampus that allow the brain to have its own GPS system. His discovery is said to have a major impact on Alzheimer's research and other brain diseases.

The Irish-born professor speaks of his surprise at learning he had become Ireland’s latest Nobel Laureate.Trinity College Dublin