As the COVID-19 virus infects and copies itself, some of its genes may change. When this happens, the new version of the virus is called a variant. Variants can make the virus better at infecting people. They can also cause people to get sicker or spread the virus more easily. Variants can even make vaccines that prevent or treat the virus less effective.
Scientists across the world track these changes, which are called mutations, to see how they affect the virus. They also use the genetic information from the virus to predict whether the vaccines and medicine that are available will work against it.
The main COVID-19 variant in the United States is omicron, but it has many offshoots (called sublineages). These have different characteristics and spread differently.
Omicron has several mutations that make it more likely to infect and spread within humans. These include a change in an amino acid that affects the way the virus sticks to cells. It also has a change that makes it less likely to be neutralized by antibodies.
Vaccines that target the spike protein have had a significant impact on the number of cases and hospitalizations related to the virus. But omicron has other mutations that can lead to a severe infection even in people who have been vaccinated.
CDC’s laboratory network is sequencing specimens from patients and testing them for the presence of COVID-19. The results are shared with other laboratories in New York State through GISAID. These data are complementary to wastewater variant data, which is collected and analyzed by participating wastewater treatment plants.