But that goal evaporated in recent weeks as the Delta variant spread rapidly, putting pressure on hospitals in regions with low vaccination rates, including many politically conservative areas in the south. Southern Missouri and Northern Arkansas, for instance, have been hard hit, swamping hospitals.
In recent weeks, there has been an uptick in the vaccination rate in some states where cases have crested. Arkansas, Missouri, Louisiana and Florida have seen steady increases.
The Delta variant is much more contagious that other forms of the virus, and may cause more severe disease, according to an internal presentation circulated recently within the Centers for Disease Control and Prevention.
Experts say that infections in vaccinated people are still relatively uncommon, and even in those cases, the vaccines currently authorized in the United States appear to provide protection against severe illness and death.
Last week, federal health authorities issued new guidelines urging fully vaccinated people to wear masks indoors because breakthrough cases of the Delta variant might be able to transmit the virus onward.