Long COVID: what is known and what gaps need to be addressed.

ABSTRACT

INTRODUCTION: Long COVID is a chronic condition that follows after acute COVID-19 and is characterized by a wide range of persistent, cyclic symptoms. SOURCES OF DATA PubMed search for publications featuring 'Long COVID' or 'post-acute sequelae of COVID-19'. AREAS OF AGREEMENT Long COVID occurs frequently post-acute COVID-19, with a majority of people experiencing at least one symptom (such as cough, fatigue, myalgia, anosmia and dyspnoea) 4 weeks after infection. AREAS OF CONTROVERSY The specific symptoms and the minimum duration of symptoms required to be defined as Long COVID. GROWING POINTS There is a consistent reduction in Long COVID incidence amongst vaccinated individuals, although the extent of this effect remains unclear. AREAS TIMELY FOR DEVELOPING RESEARCH There is an urgent need to understand the causes of Long COVID, especially extreme fatigue more than 6 months after infection. We must understand who is at risk and whether reinfections similarly risk Long COVID.