New York, Aug 29 (IANS): Covid-19 is not a respiratory illness, as widely accepted, but a vascular one, claims a study.

The study, led by the University of California-San Diego, could explain blood clots in some Covid patients and other issues like "Covid feet", which are not typical symptoms of a respiratory illness, Euronews reported.

The findings, published in the journal Circulation Research, showed how the virus attacks the vascular or circulatory system.

The S protein of the virus, the spike that forms the crown, attacks the receptor ACE2, damaging the mitocondrias that generate the energy of the cells, thus damaging the endothelium, which lines the blood vessel.

This is something that has already been observed, but what wasn't previously known is the exact mechanism and role of the S protein. This protein is replicated by all of the currently available vaccines, the team said.

For the study, the team created a pseudovirus for the study, which only had the S protein but not the rest of the virus, to show in the lab that this protein is enough by itself to cause disease.

The effects on the respiratory system are a consequence of the inflammation of the vascular tissue in the lungs.

"A lot of people think of it as a respiratory disease, but it's really a vascular disease," Uri Manor, assistant research professor, at the varsity was quoted as saying.

"That could explain why some people have strokes, and why some people have issues in other parts of the body. The commonality between them is that they all have vascular underpinnings," Manor added.

According to Professor Rafael Manez Mendiluce, head of intensive care at Bellvitge University Hospital in Spain, the vascular problem could be related to the inflammatory response of the patient's immune system.