Viruses change over time, or “mutate.” The COVID-19 virus has changed through many mutations. These changes are normal and occur when viruses spread between people.

When a person with COVID-19 coughs, sneezes or sings, the virus leaves their body in droplets. Those droplets can land on the face of someone nearby, causing them to inhale the coronavirus and get sick. People can also be infected through contact with saliva or sweat from someone who is sick. Viruses can also spread by touching a surface that has virus on it, such as a door handle or sink.

A specific mutation in the virus allows it to spread more easily. Those changes increase the number of infections, illness and death. In 2021, a new version of the virus, called Omicron, emerged in Africa and quickly spread globally. It was more contagious than previous variants and caused more severe symptoms, including pneumonia and heart failure.

In order to identify the specific COVID-19 variant that infected a person, scientists map out the genetic code of the virus (known as sequencing). Then they look for similarities or differences between the virus type and other virus types. Variants of interest and variants of concern are those that may cause more cases, be harder to treat or spread, or have other public health impacts.

The Wadsworth Center, alongside other laboratories across the state, select positive COVID-19 tests for sequence analysis. The sequence data are then shared in a publicly available database, called GISAID.