New coronavirus infections fell by roughly 16% over the past week in the U.S. — a big improvement after weeks of stasis.

The big picture: More than half of American adults have gotten at least one dose of a coronavirus vaccine, and that seems to finally be putting a dent in the size of the country’s outbreak.

By the numbers: The U.S. averaged about 55,000 new cases per day over the past week, down from about 66,000 per day the week before.

• The number of new infections declined in 26 states and only rose in four.
• New York and Michigan saw the biggest improvements; new cases were down by about 30% in both states.

What’s next: The U.S. will never totally eliminate COVID-19, but high vaccination rates and low case rates will help the country get back to normal more quickly, and will also help limit the threat that new variants of the virus will pose in the years to come.

Each week, Axios tracks the change in new infections in each state. We use a seven-day average to minimize the effects of day-to-day discrepancies in states’ reporting.