No longer overlooked: Yvonne Barr, who helped discover a cancer-causing virus

This article is part of Overlookeda series of obituaries about notable people whose deaths, beginning in 1851, were not reported in The Times.

Yvonne Barr was a 31-year-old research assistant looking for a new challenge when she was hired by a pathologist in London in 1963 to help find the cause of an unusual malignancy: exceptionally large facial tumors in Ugandan children.

Pathologist Anthony Epstein was almost certain that the tumors were caused by a virus, but he struggled to prove his hypothesis.

Barr was known by then for her superior laboratory skills, having worked on the bacterium that causes Hansen’s disease, commonly called leprosy, and other projects.

Although she had mastered cell culture techniques – essentially promoting the growth of cells under controlled conditions – Epstein had problems supporting the growth of cells in his laboratory.

“This was a key to the research: multiplying cells that can continue to grow and become experimental specimens,” says Gregory J. Morgan, author of “Hunters of cancer viruses: A history of tumor virology” (2022). “Yvonne Barr had experience producing and caring for cell cultures before she came to Epstein’s lab in 1963, and perhaps that’s why he hired her.”

Together they would make one of the most important scientific discoveries of the 20th century: the first virus to cause cancer in humans, which became known as the Epstein-Barr virus.

Epstein’s death last month was noted by news media around the world. But when Barr died in 2016, few newspapers reported it, most likely because shortly after discovering the virus in 1964, she transitioned to a quiet career in teaching, which she pursued for decades.

Barr had first sought research positions in Australia, where she had moved with her husband, but could not find any.

“Her case illustrates the pervasive sexism of mid-20th century biomedicine,” said Morgan, an associate professor of history and philosophy of science at the University of Washington. Stevens Institute of Technology in Hoboken, NJ “She found science in Australia to be a bit of a boys’ club and couldn’t get a permanent job.”

Yvonne Margaret Barr was born on March 11, 1932 in Carlow, Ireland, about an hour southwest of Dublin, the eldest of four children of Robert and Gertrude Barr. Her father was a bank manager.

She graduated from Banbridge Academy in Northern Ireland as Head Prefect, a position awarded to students who were designated as leaders and mentors. At Trinity College, Dublin she shone again, obtaining a degree in zoology and graduating with honors in 1953.

It was through jobs as a research assistant from 1955 to 1962 that she acquired her laboratory skills. At London’s National Institute for Medical Research, she worked on the bacterium that causes leprosy and learned the cell proliferation technique known as cell culture.

A second position, as a research assistant at the University of Toronto, provided another opportunity to hone laboratory skills in experiments with canine distemper virus, a pathogen that can cause a serious and often fatal infection in both dogs and other animals.

But while Barr mastered cell culture techniques, Epstein, who worked at the Middlesex Hospital Medical School in London, struggled with them, Morgan said.

In 1963, Epstein received a $45,000 research grant from the U.S. National Institutes of Health and hired Barr and Bert Achong, an expert in electron microscopy. Both would earn doctorates while working in Epstein’s laboratory.

Epstein was already working with Denis Burkitt, a surgeon and Presbyterian missionary in Uganda, who sent tissue samples to London from biopsied facial tumors affecting Ugandan children.

The cancer was known as Burkitt lymphoma, and because the tumors occurred in certain equatorial locations, Epstein strongly suspected a viral cause. What he needed was a more effective way to grow cells that might harbor the virus.

Barr’s techniques allowed the team to maintain clusters of cells. Their research was the first to use cell culture techniques to study human B cells, which are affected in Burkitt lymphoma, Morgan said.

In July 2022, The Irish Times quoted Barr explaining why she thought Epstein’s early efforts did not work. “By the time I arrived at the Middlesex I had a lot of experience with tissue culture,” she wrote in an undated recollection. “I had the feeling that Epstein was throwing away the good cells. I applied my methods and gave the cells a wash and new food every few days.’

A tumor sample from Burkitt that initially seemed doomed after fog at Heathrow Airport delayed delivery turned out to be the sample that contained definitive evidence of a causative virus.

“One day some of them glistened, and people thought that was a sign of life,” Barr, speaking from Australia, told a video conference in London in 2014. “There was great excitement, and it was about getting enough for electron microscopy.”

Achong captured a clear image of that cell cluster, and Epstein immediately recognized the clear signature of a herpes virus new to science. The perpetrator was found. Researchers from the University of Pennsylvania confirmed the results.

“The virus is named after the cell culture in which it was found,” Morgan explains. “The cell cultures were labeled EB1, for Epstein Barr 1, EB2, EB3, etc.”

Epstein-Barr virus, or EBV, is also the cause of mononucleosis and is strongly associated with Hodgkin’s lymphoma. It is estimated that 90 percent of the world’s adult population are carriers of the virus.

Barr received her PhD in 1966, a year after her marriage to Stuart Balding, an industrial chemist. After emigrating to Australia, they had two children, Kirsten and Sean Balding. She earned a teaching degree and became a high school math and science teacher. Her work in biomedical research had ended with the discovery in Epstein’s laboratory.

“She regarded the discovery as a small part of her life,” Kirsten Balding said in an interview. “I think she loved being a teacher and helping kids.”

Barr died on Feb. 13, 2016, in Melbourne after developing multiple medical problems, including diabetes and congestive heart failure, her daughter said. She was 83.