The global clinical studies of long COVID.

People with long COVID are those who still have symptoms, signs, and conditions after the initial phase of infection of SARS-CoV-2. The incidence of long COVID varies among regions-31% in North America, 44% in Europe, and 51% in Asia, which is challenging the healthcare system, but there is limited guidelines for its treatment. With more and more nationwide projects funded by the government such as the RECOVER initiative in the United States and National Institute for Health Research funding in the United Kingdom, an increasing number of ongoing clinical trials are investigating the efficacy of diverse therapies on reversing long COVID.