From the early days of the pandemic, doctors noticed that in severe cases of Covid-19 – the ones that landed people in the hospital on ventilators with shredded lungs – most of the internal wreckage wasn’t being directly inflicted by the virus itself but by a blizzard of immune reactions triggered by the body to fight the infection.
Researchers knew that these so-called cytokine storms were damaging, but they didn’t know why the SARS-CoV-2 virus seemed to be so good at setting them off.
A new study published [April 6] in the journal Nature is helping to explain how these immune overreactions happen to Covid-19 patients.
The study revealed that the SARS-CoV-2 virus can infect certain kinds of immune cells called monocytes and macrophages.
Monocytes and macrophages are white blood cells, and they are frontline workers of the immune system.
“The viruses not only get taken up, but once they get taken up, the virus starts replicating, so that was surprising,” said Dr. Judith Lieberman, a pediatric immunologist at Boston Children’s Hospital, who led the research.
A virus starting to make copies of itself in the body is never a good thing, but when this happens to these protector cells, it sets off a next-level set of alarms.
