WASHINGTON - The United States has witnessed the lowest single-day increase of COVID-19 cases and deaths since last winter as vaccination efforts are accelerated across the nation.

A total of 40,428 new cases and 589 deaths were reported across the country on Sunday, according to data updated Monday by the US Centers for Disease Control and Prevention (CDC).

The daily increase of new cases marked the lowest since Oct 6 last year, while the new deaths count was the lowest since Nov 15.

Currently, the country averages about 65,000 daily increase of cases and 1,200 deaths, CDC data show.

Key COVID-19 indicators have continued to drop since January. Since the highest seven-day average daily cases of 249,378 on Jan 11, the seven-day average increase of new cases decreased by 78.1 percent, according to the CDC.

Meanwhile, there has been an overall decline of 56.6 percent of the seven-day average of new deaths since Jan 13, CDC data show.

Hospital admissions of COVID-19 patients fell by 70.4 percent from the national seven-day average peak of 16,540 admissions on Jan 9 to 4,889 admissions over the week ending March 9.

The average number of daily admissions fell by 11 percent compared to the previous week, according to the CDC.

The sign of progress came as the country has been ramping up COVID-19 vaccines rollout.

As of Monday, over 135 million vaccine doses have been distributed across the country, and more than 109 million doses have been administered, according to the CDC.

More than 38 million Americans have been fully vaccinated.

US President Joe Biden announced last week that he will direct all states, tribes, and territories to make all adult Americans eligible for COVID-19 vaccines by May 1.

Public experts have warned the public not to let down their guard and maintain strict protective measures against increasing variants infections.