EBV The enemy that lives inside our bodies

Epstein-Barr virus is a decisive factor in multiple sclerosis and linked to cancer. Can the lessons of Covid help to eradicate this common infection?

- David Cox

Hank Balfour, a virologist at the University of Minne-sota Medical School, was studying the long-term survival prospects of kidney transplant patients when he noticed that a small proportion of them went on to develop a rare form of cancer known as post-transplant proliferative disorder.

He was particularly intrigued when he discovered, back in the 1970s, that almost all of these patients had been infected with a virus called EpsteinBarr or EBV, a curious pathogen that has captivated and puzzled virushunters for decades.

“EBV can maintain latency within human cells,” says Balfour. “When we began studying it, it seemed that certain people were more prone to difficulties managing the virus immunologically, perhaps due to their genetic makeup, which allows the virus to put a damaging footprint on the immune system, causing long-term problems.”

“ Hit-and-run” viruses such as Ebola or Sars-CoV-2 – which invade organs, wreaking havoc in their wake, before leaving the body – tend to make headlines in the virology world. EBV, meanwhile, is a classic example of a “hitand-stay” virus. This sort of infection silently assimilates within the body’s tissues, in such a way that it is nigh on impossible for the immune system to get rid of it, meaning it remains with its host for the rest of their lives.

Exactly what the se viruses do and how they affect health has long been a mystery, but there is mounting evidence that EBV is not benign. It evolved to coexist with humanity over millions of years. It has become adept in hiding in B-cells, which are part of the immune system and where it stays for decades.