President Joe Biden is urging Americans to ทางเข้าxo get jabbed as Covid infections rise across the country.
But in some states fewer than half of residents have received their first dose.
We've looked into where vaccinations are lagging, and why this might be.
US falling behind
Supply isn't generally a problem in the US, and anyone over the age of 12 is eligible to receive an authorised vaccine.
But after being one of the world leaders in vaccine uptake until the middle of April, the US vaccination rate has slowed down.
The US now lags behind neighbouring Canada in terms of doses administered as share of total population, as well as the UK, Italy and Germany.
It's still ahead of some major economies such as Japan, but the vaccination rate in the US is dropping off more significantly than in other developed countries.
What states are lagging behind?
States in the south of the US tend to have the lowest vaccine uptake.
Mississippi has the lowest - with less than 40% of residents having received at least one dose.
North-eastern states tend to have among the highest vaccine uptake - with about 75% of people in Vermont, Massachusetts and Connecticut receiving at least one dose.
Prof Peter Hotez, a vaccine expert at the Baylor College of Medicine, says: "It's practically halted in the southern states - despite the widespread availability of the vaccine, we have a sharp divide."