HIV is a retrovirus that impairs the immune system and causes AIDS. Learn about symptoms and treatment.
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.
Vaccines activate the immune system, training it to fight off certain viral and bacterial infections.