The omicron wave that assaulted the United States this winter also bolstered its defenses, leaving enough protection against the coronavirus that future spikes will probably require much less if any dramatic disruption to society, scientists say.
There are four medications being used to help prevent hospitalizations. But supply has been so limited, even people in the highest risk category can't always access them. That's beginning to change.
With the arrival of the contagious Delta variant, Covid hospitalizations and deaths among vaccinated Americans also may have increased, according to preliminary figures.
Although in small numbers, breakthrough infections accounted for at least one in 5 newly diagnosed cases in six of these states and higher hospitalisation and death rates.