["Long-haul COVID": An opportunity to address the complexity of post-infectious functional syndromes]

In this work, we address the issue of prolonged symptoms following an infection by SARS-CoV-2, labeled "long COVID". This clinically unspecific syndrome must be put in perspective with the post-infectious syndromes known for a long time but ultimately poorly understood and little studied, qualified, for lack of convincing arguments for a unambiguous pathophysiology and better terms, as functional somatic syndromes. The clinical implications for clinical care ("holistic" work-up and care of patients), for research (need for truly "bio-psycho-social" investigations), and the social implications of "long COVID" (social construction of the syndrome through the experiences of patients exposed on social networks, inequalities in the face of the disease and its socioeconomic consequences) are considered. "Long COVID" must be view, because of its expected prevalence, as an opportunity to address the complexity of post-infectious (functional) syndromes, their risk factors, and the biological, psychological and social mechanisms underlying them.