Long COVID refers to new or recurring symptoms that occur four or more weeks after an infection with SARS-CoV-2, the virus that causes COVID-19.
COVID-19 is the disease caused by the SARS-CoV-2, the 2019 novel coronavirus.
Coronavirus is a term describes a family of viruses, common in both animals and humans.
The flu is a common contagious viral infection that attacks the respiratory system. Learn about symptoms and treatment.