COVID-19 patient helps scientists map virus immune response

A woman, who recovered in 10 days, produced white blood cells that targeted virus-infected cells and spurred the production of antibodies.

Representational Image | Commons

Melbourne: A Covid-19 patient in Melbourne underwent a barrage of tests to map her broad range of immune responses to the coronavirus, providing clues about the body’s ability to battle the pneumonia-causing pathogen.

Blood samples tested at four different time points showed the 47-year-old woman produced white blood cells that targeted virus-infected cells and spurred the production of antibodies that drove her recovery 10 days after developing a mild-to-moderate illness that required hospitalization.

Her case, reported Monday in the journal Nature Medicine, and a handful of others studied by researchers at Melbourne’s Peter Doherty Institute for Infection and Immunity are helping to identify immune-system patterns that might help doctors detect the one-in-five patients likely to develop a severe or critical form of Covid-19.

“We will need to analyze a large number of Covid-19 patients,” said Katherine Kedzierska, a professor of microbiology and immunology at the University of Melbourne who co-authored the paper. “But it is possible that,having all the data, we might find immune markers predicting recovery, which would be really important to know which patients are at risk of severe Covid-19 disease when they get admitted to the hospital.”

Blood tests on the patient, who had traveled from the central Chinese city of Wuhan before becoming ill in Melbourne, indicated she produced some inflammation in response to the novel coronavirus, but not the potentially lethal, out-of-control form that can destroy healthy tissues.

“Her immune responses did a great job,” said Kedzierska, who has been studying the immune response to viral infections for the past 20 years, in a phone interview. The patient’s controlled inflammation avoided high levels of so-called cytokines and chemokines — proteins that indicate inflammation is flaring out of control.

Kedzierska and colleagues detected antibodies against the Covid-19 virus in the patient’s blood before her symptoms resolved. The researchers are now working to understand the “immunological memory” of the infection. That will offer clues about whether the patient’s antibody response is sufficient to protect her against a subsequent infection, and if so, for how long.

The findings will also inform methods to appraise the development of protective vaccine candidates, the researchers said. -Bloomberg