This early research looks at what happens when cells within the small blood vessels of the heart are exposed to high levels of the spike protein in a laboratory setting. It could help to start to explain some of the effects of severe Covid-19 infection, where levels of the virus are particularly high.

Background Severe coronavirus disease 2019 (COVID-19) manifests as a life-threatening microvascular syndrome. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) uses primarily the capsid spike (S) protein to engage with its receptors and infect host cells. To date, it is still not known if the S protein alone, without the other viral elements, is able to trigger vascular cell signalling and provoke cell dysfunction.