About the Delta Variant: Vaccines are highly effective against severe illness, but the Delta variant causes more infections and spreads faster than earlier forms of the virus that causes COVID-19.
Viruses constantly change through mutation, and new variants of a virus are expected to occur. Sometimes new variants emerge and disappear. Other times, new variants persist. Numerous variants of the virus that causes COVID-19 are being tracked in the United States and globally during this pandemic.
Scientists monitor all variants but may classify certain ones as variants of interest, concern, or high consequence based on how easily they spread, how severe their symptoms are, and how they are treated.
Some variants seem to spread more easily and quickly than other variants, which may lead to more cases of COVID-19. An increase in the number of cases will put more strain on healthcare resources, lead to more hospitalizations, and potentially more deaths.
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.