(AP) — COVID-19 deaths in the United States 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, on some days, hitting zero.

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, reported cases have plummeted 85% from a daily peak of more than a quarter-million in early January.

The last time U.S. deaths from the pandemic were this low was in early July of last year. The number of people with COVID-19 who died 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 its front page Wednesday under the headline “First time in nearly a year state has no new coronavirus deaths.” Indiana reported one COVID-19 fatality Tuesday. Kansas, which peaked at 63 reported deaths on Dec. 22, has been in the single digits since February and seen multiple days with just one virus-related death.

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. This week, Pfizer’s vaccine won authorization for use in 12- to 15-year-olds, a move that could make it easier to reopen the nation’s schools.

Physicians like Dr. Tom Dean in South Dakota’s rural Jerauld County are cautiously optimistic, concerned about the many people who have decided against getting vaccinated or have grown lax in guarding against infections. The county has recorded just three confirmed cases in the last two weeks, according to Johns Hopkins data.

“What I’m afraid of is people believing this whole thing is over and you don’t have to worry about it any more,” Dean said. “I think complacency is our biggest threat right now.”

Several states, including Wyoming, Vermont, Alaska and Hawaii, were averaging fewer than one COVID-19 death per day over the past week, according to data through Tuesday from Johns Hopkins.

And even among the five states with the highest daily deaths — Michigan with an average of 65.4, Florida with 61.7, California with 48, Texas with 44 and New York with 39.3 — all but Florida’s number were going down.

California, the epicenter of the U.S. outbreak over the winter, logged 1,231 new confirmed cases Wednesday, down from a peak of 40,000. Los Angeles County reported 18 deaths Tuesday, versus more than 200 a day in January.

Vermont, which at nearly 63% leads the country in the share of its population that has received at least one vaccine dose, has gone nearly a week without reporting a COVID-19 death.

The improvement hasn’t been as dramatic everywhere. Michigan, which for weeks has reported the nation’s worst infection rate, is only now starting to see a decline in mortality. But over the past two weeks, cases in the state plunged from a daily average of almost 4,860 to about 2,680 on Monday.

“Every day we’re getting closer to putting this pandemic behind us,” Michigan Gov. Gretchen Whitmer said.