The Delta variant causes more infections and spreads faster than the original SARS-CoV-2 strain of the virus that causes COVID-19. The Omicron variant likely will spread more easily than the original SARS-CoV-2 virus, but how easily Omicron spreads compared to Delta remains unknown. The CDC expects that anyone with Omicron infection can spread the virus to others, even if they are vaccinated or don’t have symptoms.
Vaccines remain the best way to reduce your risk of severe illness, hospitalization, and death from COVID-19. Current vaccines are expected to protect against severe illness, hospitalizations, and deaths due to infection with the Omicron variant. However, breakthrough infections in people who are fully vaccinated are likely to occur. With other variants, like Delta, vaccines have remained effective at preventing severe illness, hospitalizations, and death. The recent emergence of Omicron further emphasizes the importance of vaccination and boosters.
Masks offer protection against all variants. CDC continues to recommend wearing a mask in public indoor settings in areas of substantial or high community transmission, regardless of vaccination status.
For more information, visit the CDC’s page on variants.