COVID-19 pandemic - Wikipedia
In epidemiology, a pandemic is defined as "an epidemic occurring over a very wide area, crossing international boundaries, and usually affecting a large number of people". During the COVID-19 …
How to Protect Yourself and Others | COVID-19 | CDC
Mar 10, 2025 · CDC’s Respiratory Virus Guidance provides strategies you can use to help protect yourself and others from health risks caused by COVID-19 and other respiratory viruses. These …
COVID-19: From How You Get It to How You Treat It
Sep 26, 2025 · COVID-19 is a vaccine-preventable disease mainly spread by respiratory droplets. While most have mild symptoms, others may get severely ill and need medical treatment.
What Does the 19 Mean in COVID-19? - Biology Insights
Dec 9, 2025 · The number “19” in COVID-19 refers to the year 2019, specifically the year the outbreak was first identified and reported to the world. The earliest known cases of the illness appeared in …
Coronavirus disease 2019 (COVID-19) - MedlinePlus
Jan 1, 2025 · COVID-19 is caused by a highly infectious virus. Most people get mild to moderate illness. Older adults and people with certain health conditions are at high risk for severe illness and death. …
COVID-19: How can I protect myself? - Mayo Clinic
Oct 24, 2025 · Coronavirus disease 2019 (COVID-19) is caused by a virus that spreads between people. Find out how to protect yourself and those close to you.
Quick Facts: COVID-19 - Merck Manual Consumer Version
COVID-19 is a potentially severe viral infection that mostly affects your lungs and airways. What causes COVID-19? COVID-19 is caused by a type of coronavirus called SARS-CoV-2. The virus spreads: …