Like all viruses, COVID-19 mutates as it spreads. Mutations are changes in the virus’s genetic code. The virus may mutate to get better at infecting people, spread faster or cause more illness or death. Virologists study the mutations to learn more about how the virus affects us. Some mutations disappear while others keep showing up. We refer to the more significant variants as Variants Being Monitored, Variants of Concern and Variants of Interest.
The newest COVID-19 variants are called Gamma, Delta and Omicron. CDC is monitoring the spread of these variants because they appear to be more contagious and could lead to more cases. More cases mean more strains on health care resources and can lead to hospitalizations, serious medical complications and even death. These new variants also cause subtly different symptoms, making it harder to know when a person is infected.
CDC scientists are tracking these variants as they develop by sequencing the DNA of COVID-19 specimens. Many laboratories across the country and in New York state do this work. The sequence data are shared with the public through a database called GISAID. The Wadsworth Center contributes to this database.
This database includes information about the year, month and sample source where a particular variant was first detected. It also lists mutations in the spike protein – the part of the virus that attaches to cells and infects them. It lists mutations that can help evade neutralizing antibodies, such as a mutation at 456 in the S protein that eliminates binding sites for the antigen that causes the body to make antibodies against the virus.