As the COVID-19 pandemic continues, the virus is constantly changing. Whenever a new mutation occurs in the virus, it can make the virus spread more easily or cause more severe illness. Scientists around the world are tracking these changes, called variants, to learn more about how they spread.
Variants can also change how a person may feel. If a person gets sick with one variant and then catches another, they could have different symptoms, like chills, cough, body ache, fatigue or nausea. Some variants can even lead to serious health problems, like pneumonia and encephalitis.
During the initial COVID-19 outbreak, scientists discovered many variants. These viruses have different genetic differences, or mutations, from the original SARS-CoV-2 virus that caused the first outbreak. Each of these different virus strains has a name and is tracked by scientists. They are usually classified as part of a lineage, or family, with the original SARS-CoV-2 virus being the parent. Some are then given a sublineage name, or a number.
The most well-known COVID-19 variants are Alpha (B.1.1.7) and Delta (B.1.351). Alpha exploded in infections in Great Britain in late 2020, but then faded away as the Delta variant took over. Delta has more mutations that allow it to evade antibodies and pass on infection more quickly than other COVID-19 variants. It is especially dangerous for unvaccinated people.
The other major variant is omicron, which arrived this past summer. Omicron is spread more easily than the original virus and delta, but seems to cause less severe disease. Omicron has several offshoots, or sublineages, that made up the majority of cases in the United States this year.