- COVID-19 causes respiratory symptoms similar to a cold or the flu.
- Most people experience mild symptoms, but some people become severely ill.
- Some people including those with minor or no symptoms may suffer from post-COVID conditions also known as “long COVID”.
- Older adults and people who have certain underlying medical conditions are at increased risk of severe illness from COVID-19.
- Hundreds of thousands of people have died from COVID-19 in the United States.
- COVID-19 vaccines are safe and effective. Vaccines teach our immune system to fight the virus that causes COVID-19.
SARS-CoV-2 – the virus that causes COVID-19
Like many other respiratory viruses, coronaviruses spread through droplets that you project out of your mouth or nose when you breathe, cough, sneeze, or speak.
The word corona means crown and refers to the appearance that coronaviruses get from the spike proteins sticking out of them. The spike protein is the part of the virus that attaches to a human cell to infect it, allowing it to replicate inside of the cell and spread to other cells.
As genetic changes to the virus happen over time, the SARS-CoV-2 virus begins to form genetic lineages, like a family tree. Scientists call the viruses with these changes “variants”. Variants such as the Delta variant and Omicron variant are still SARS-CoV-2 but may act differently. Differences in variants include how fast the virus spreads, the severity of illness it causes, or the effectiveness of treatments against it.