Would Covid cause long-term deterioration?

VIENNA (EFE).— Infection with the Covid-19 virus weakens the immune system in the long term, leading to “a significant reduction in immune cells in the blood,” according to a new study by Austrian scientists.

The findings of the study, conducted by experts at the Medical University of Vienna (UniMed) and published yesterday in the specialist journal “Allergy”, point to a long-term deterioration in the function of bone marrow, the central site of production of immune cells.

These results reveal that the immune system of patients who have recovered from a Covid-19 infection may have stopped responding optimally, UniMed highlights in a statement.

The effects of a confirmed SARS-CoV-2 infection at work have been observed even in mild cases of the disease and will be the basis for further research into long-term Covid.

“Our results provide a possible explanation that certain long-term consequences of Covid-19 could be related to damage to the cellular immune system” caused by the virus, says Professor Winfried Pickl, head of the research team, in the note.

More specifically, the cause may be the “apparently reduced maturation and/or emigration of immune cells from the bone marrow,” he added.

“Even after mild courses of the disease, we found a significant reduction of immune cells in the blood,” the immunologist emphasizes.

The study, which began in 2020, examined relevant immune parameters in 133 people who had recovered from Covid-19 and 98 people who had not had the infection.

The number and composition of various immune cells, as well as growth factors in the blood, which play a key role in regulating cell growth, were analyzed in patients who recovered ten weeks and ten months after contracting the disease.

Since no vaccines against Covid-19 were available at the start of the study, all participants were unimmunised. “Not entirely unexpectedly, ten weeks after infection, recovered patients showed clear signs of immune activation in both T and B cells (white blood cells), in contrast to healthy test subjects,” says Pickl.

It was the samples from patients taken ten months after the illness that surprised the scientists, as they showed “a significant reduction in immune cells.”