WASHINGTON — New filings for US unemployment benefits slid lower for a fourth straight week, reaching a new pandemic low as Covid-19 vaccines help the economy rebound, the government said Thursday.

The Labor Department said 406,000 new seasonally adjusted claims for jobless benefits were made last week, 38,000 fewer than the previous week’s unrevised total and fewer than analysts had expected.

The report brings the closely watched indicator of labor market strength closer to the pre-pandemic level of 256,000 seen on the week of March 14, 2020 — before the spreading coronavirus forced businesses to close and unemployment filings skyrocketed into the millions.

The data also said the insured unemployment rate, indicating workers receiving benefits, ticked down slightly to 2.6 percent, with more than 3.6 million people receiving regular aid as of the week ended May 15.

However that was 96,000 fewer than the week before, the biggest one-week drop since March.

“While the recovery in the labor market may be uneven at times, the declines in both initial and continuing claims are a clear sign that progress is ongoing,” Nancy Vanden Houten of Oxford Economics said.

The data showed another 93,546 people, not seasonally adjusted, made new claims last week for Pandemic Unemployment Assistance, which gives aid to freelancers who are not normally eligible, slightly less than the week prior.

Despite the improvements, more than 15.8 million people were receiving benefits under all programs as of the week ended May 8, a reminder of that unemployment remains widespread.