Job openings in the U.S. plateaued in late summer at records as the Delta variant of Covid-19 curtailed previously strong demand for restaurant, salon, and other in-person service positions.

Postings on job-search site were up about 39% at the end of August from February 2020, ahead of the pandemic. That marked a modest gain from the comparable week of July, when postings were up 37% from February 2020.

Help WantedChange in job postings from February 2020Source: Indeed.comNote: Seven-day average
March 2020'21-40-30-20-10010203040%

The August gain was largely driven by increased demand for jobs that can be done from home, such as software development. Postings for child care fell and openings in construction and at restaurants rose only slightly.

“There was a pretty clear reversal of fortune in pandemic-sensitive sectors,” said Indeed economist Nick Bunker. Categories such as foodservice and tourism had driven overall gains in job openings during the first half of the year. At the time, widespread availability of vaccinations increased consumer confidence and raised the prospect that the economy would soon fully reopen, he said.

That changed in August.

“The Delta variant has thrown a wrench into things and the pace of postings has slowed down,” Mr. Bunker said.

The Labor Department will release its accounting of job openings at the end of July at 10 a.m. ET on Wednesday. Economists surveyed by The Wall Street Journal expect the report to show 10.1 million unfilled jobs. That would match June as the highest level recorded in data going back to 2000.

Data from Indeed showed that postings for beauty and wellness jobs, such as those done in salons and spas, fell 8.5% during August after jobs in those industries had returned to a pre-pandemic level in the prior month. Job openings in child care fell 3.3%. Openings for food-services positions were up 0.7% in August, after strong gains earlier in the year. Hospitality and tourism jobs grew by just less than 4% in August.

That is a contrast from the spring when businesses ramped up as more people received vaccinations. For example, job postings in food service rose 11.4% in the four-week period ended April 23, and hospitality and tourism openings rose 14.3%

The Indeed data is in line with the Labor Department’s August jobs report, which showed bars and restaurants cut 41,500 jobs last month while child-care employers shed 6,000 positions.

Postings for jobs that can largely be done from home—mainly white-collar occupations—increased in August, according to Indeed. Software development postings rose 19% in August, it said, while those for human resources jobs were up 13.2%. Banking and finance postings increased 10.8%.

Strong demand for professional jobs indicates companies are optimistic about the economy’s medium-term growth prospects, despite near-term uncertainty due to the Delta variant, Mr. Bunker said.

It is a repeat of a dynamic seen earlier in the pandemic when those who could work from home were less likely to experience job loss and saw labor-market prospects that were similar to the picture before the pandemic.

“It’s like we’re climbing a spiral,” Mr. Bunker said. “We’ve made some progress, but a lot of this looks familiar. An uptick in the virus is going to hit those with lower-paid jobs, who tend to have lower levels of education.”