SARS-CoV-2 (blue) invades human cells, grown in the laboratory / Colored microscopic image. Photo: Reuters

(RT) The death rate from COVID-19 is almost ten times higher than that of the common flu, although it is less fatal in itself.

The virus that causes the disease that has claimed the lives of nearly 690,000 people worldwide — does not appear to be “a killing machine,” say scientists at the University of California, San Francisco (UCSF).

“One of the weirdest things about this new coronavirus is that it doesn’t appear to be incredibly cytopathic, by which we mean cell death,” UCSF professor Max Krummel said in a press interview.

“The flu is really cytopathic; if you add [the influenza virus] to human cells in a Petri dish, the cells explode in 18 hours,” says Krummel.

Instead, when the UCSF researchers added the Covid-19 virus to a Petri dish with human cells, many of the infected cells did not die for a long time.

Krummel asserts that this fact represents “pretty compelling data that we may not be dealing with a very aggressive virus.”

So why do Covid-19 patients die?

At UCSF they suspect that the primary cause of death for covid-19 patients may be their own immune system, which goes into overdrive to attack the virus.

As a result, patients’ lungs are “devastated” not only by the virus, but by this “immune battle that went wrong,” scientists say.

This ‘unauthorized’ immune response may explain why, around day 11 of a Covid-19 infection, patients often develop severe pneumonia known as ‘acute respiratory distress syndrome’ or ARDS, which can lead to death.