Variants of Concern

Alpha - B.1.1.7

First identified: United Kingdom
Spread: Spreads much faster than other variants
Severe illness and death: May potentially cause more people to get sicker and to die
Vaccine: Currently authorized vaccines do work against this variant. Some breakthrough infections in fully vaccinated people are expected but remain rare. All vaccines are particularly effective against severe illness, hospitalization, and death
Treatments: Treatments are effective against this variant

Beta - B.1.351

First identified: United Kingdom
Spread: Spreads much faster than other variants
Severe illness and death: May potentially cause more people to get sicker and to die
Vaccine: Currently authorized vaccines do work against this variant. Some breakthrough infections in fully vaccinated people are expected but remain rare. All vaccines are particularly effective against severe illness, hospitalization, and death
Treatments: Treatments are effective against this variant

Gamma - P.1

First identified: United Kingdom
Spread: Spreads much faster than other variants
Severe illness and death: May potentially cause more people to get sicker and to die
Vaccine: Currently authorized vaccines do work against this variant. Some breakthrough infections in fully vaccinated people are expected but remain rare. All vaccines are particularly effective against severe illness, hospitalization, and death
Treatments: Treatments are effective against this variant

Delta - B.1.617.2

First identified: United Kingdom
Spread: Spreads much faster than other variants
Severe illness and death: May potentially cause more people to get sicker and to die
Vaccine: Currently authorized vaccines do work against this variant. Some breakthrough infections in fully vaccinated people are expected but remain rare. All vaccines are particularly effective against severe illness, hospitalization, and death
Treatments: Treatments are effective against this variant

Omicron - B.1.1.529

First identified: South Africa
Spread: May spread more easily than other variants, including Delta.
Severe illness and death: Due to the small number of cases, the current severity of illness and death associated with this variant is unclear.
Vaccine: Breakthrough infections in people who are fully vaccinated are expected, but vaccines are effective at preventing severe illness, hospitalizations, and death. Early evidence suggests that fully vaccinated people who become infected with the Omicron variant can spread the virus to others. All FDA-approved or authorized vaccines are expected to be effective against severe illness, hospitalizations, and deaths. The recent emergence of the Omicron variant further emphasizes the importance of vaccination and boosters.
Treatments: Some monoclonal antibody treatments may not be as effective against infection with Omicron.