Insights Into Long COVID

Some people end up with long-lasting illness after being infected with SARS-CoV-2, the virus that causes COVID-19. This is called Long COVID. Symptoms can include extreme tiredness, difficulty thinking or concentrating, and breathing problems. Researchers are trying to understand why some people get Long COVID and others do not.

To learn more, a team of scientists compared blood samples from more than 250 people. Some had been infected with SARS-CoV-2 and some had not. Among those who had been infected, some had Long COVID and some did not.

The team found that people with Long COVID had different amounts of germ-fighting immune cells and antibodies than those without Long COVID. Those with Long COVID had more antibodies that attack SARS-CoV-2. And they had stronger responses to an unrelated virus called Epstein-Barr virus (EBV). EBV is a common virus that causes mononucleosis. After infection, EBV remains in the body and can be inactive or reactivate. The researchers suggest that EBV might reactivate in some people who have Long COVID.

The study’s findings could lead to ways to help diagnose Long COVID. They also shed light on factors that could affect Long COVID.

“These findings can inform more sensitive testing for Long COVID patients and personalized treatments for Long COVID,” says study co-lead Dr. David Putrino of Mount Sinai.