Covid-19 significantly changes the size and stiffness of red and white blood cells – sometimes over months. These results may help to explain why some affected people continue to complain of symptoms long after an infection (long covid).

Shortness of breath, fatigue and headaches: some patients still struggle with the long-term effects of a severe infection by the SARS-CoV-2 coronavirus after six months or more. This post Covid-19 syndrome, also called long covid (also post-acute sequelae of COVID-19 or PASC), is still not properly understood. What is clear is that — during the course of the disease — often blood circulation is impaired, dangerous vascular occlusions can occur and oxygen transport in is limited. These are all phenomena in which the blood cells and their physical properties play a key role.

To investigate this aspect, a team of scientists led by Markéta Kubánková, Jochen Guck, and Martin Kräter from the Max-Planck-Zentrum für Physik und Medizin, the Max Planck Institute for the Science of Light (MPL), the Friedrich Alexander University Erlangen-Nuremberg and the German Centre for Immunotherapy measured the mechanical states of red and white blood cells. “We were able to detect clear and long-lasting changes in the cells — both during an acute infection and even afterwards,” reports Professor Guck, currently managing director of MPL. The research group has now published their results in the renowned journal “Biophysical Journal“.