WASHINGTON • COVID-19 deaths in the U.S. have tumbled to an average of around 600 per day — the lowest level in 10 months — with the number of lives lost dropping to single digits in well over half the states and hitting zero on some days.

Confirmed infections have fallen to about 38,000 per day on average, their lowest mark since mid-september. While that is still cause for concern, they have plummeted 85% from a peak of more than a quarter-million per day in early January. The last time deaths were this low was early July, nearly a year ago. COVID-19 deaths in the U.S. topped out in mid-january at an average of more than 3,400 a day, just a month into the biggest vaccination drive in the nation’s history.

The Boston Herald put a huge zero on Wednesday’s front page under the headline “First time in nearly a year state has no new coronavirus deaths.” Indiana reported only one COVID-19 fatality Tuesday. Kansas, which peaked at 63 deaths on Dec. 22, has been in the single digits since February and has seen multiple days with just one fatality.

Dr. Amesh Adalja, an infectious disease specialist at Johns Hopkins University, said that vaccinations have played a crucial role even as the nation struggles to reach herd immunity.

“The primary objective is to deny this virus the ability to kill at the rate that it could, and that has been achieved,” he said. “We have in effect tamed the virus.”

About 45% of the nation’s adults are fully vaccinated, and nearly 59% have received at least one dose, according to the Centers for Disease Control and Prevention.