Omicron Virus

What You Need to Know About COVID-19 Variants

New variants of SARS-CoV-2, the virus that causes COVID-19, are expected to occur.
CDC is working with state and local public health officials to monitor the spread of all variants.
The Omicron variant continues to spread throughout communities and can infect people who have been vaccinated or have previously had COVID-19.

Staying up to date with your COVID-19 vaccines reduces your risk of severe illness, hospitalization, and death from COVID-19.

Variants in the United States

Numerous variants of the virus that causes COVID-19 are being tracked in the United States and globally during this pandemic. CDC is working with public health officials to monitor the spread of all variants and provide an estimate of how common they are in the nation and at the regional level. This data can change over time as more information is available.

Variants Are Expected

Viruses constantly change through mutation and sometimes these mutations result in a new variant of the virus. Some variations allow the virus to spread more easily or make it resistant to treatments or vaccines. As the virus spreads, it may change and may become harder to stop.

Vaccines help prevent severe illness, hospitalizations, and death

Breakthrough infections in people who are vaccinated are expected. The emergence of the Omicron variant further emphasizes the importance of vaccination and boosters.

Antiviral treatments are effective

Some, but not all, monoclonal antibody treatments remain effective against Omicron. Public health agencies work with healthcare providers to ensure that effective treatments are used appropriately to treat patients.

Symptoms are similar to previous variants

COVID-19 vaccination status, other health conditions, age, and history of prior infection can affect the presence and severity of symptoms.

Omicron causes less severe illness and death in general, according to data

However, a surge in cases may lead to increases in hospitalizations and deaths.

Omicron spreads more easily than earlier variants, including the Delta variant.

Anyone with Omicron infection, regardless of vaccination status or whether or not they have symptoms, can spread the virus to others. Data suggest that Omicron can cause reinfection, even in people who have recovered from COVID-19.