Ride hailing companies Uber Technologies Inc and Lyft Inc promised Wall Street they would be back on the road to profitability and growth by the time they reported second-quarter results this week, thanks to cost-cutting done to survive the pandemic.

Now, concerns over an ongoing driver shortage and the spreading Delta variant are clouding the outlook for making good on achieving profitable operations this year.

The ride-hail companies’ core businesses are closely tied to broader economic activity and provide insights into the comfort levels of Americans and Europeans in resuming pre-pandemic activities. Uber has been moving to expand into goods and meal delivery to reduce dependence on rides.

During the second quarter, many countries reopened their economies, and analysts expect Uber and Lyft will report revenues rebounded.

But a rapid spread of the more contagious Delta variant has prompted several health authorities to reimpose some restrictions.

“The continued uncertainty around the pandemic’s trajectory will suppress both supply and demand for rideshare services until we see what the Delta variant’s death toll really is,” said Forrester analyst James McQuivey.

The Delta variant complicates efforts by both companies to achieve profitability this year on a basis of adjusted earnings before interest, taxes, depreciation and amortization. The adjustments exclude one-time costs, including stock-based compensation.

Lyft said it would achieve that target by the end of the third quarter, Uber by the end of this year.

Lyft in May said it would take advantage of its leaner cost structure to make more money per ride as passengers return to the platform in greater numbers. Uber, also in May, said it would become profitable in the second half of 2021, requiring the company to quickly reduce losses.

During the second quarter, when it appeared the coronavirus threat was receding, Uber and Lyft were focused on luring drivers back with large pay incentives. Analysts at KeyBanc Capital Markets in a note said the incentives were proving effective at getting more drivers on the platforms, allowing the companies to start strategically dialing back the extra pay. KeyBanc said its proprietary data showed guaranteed fares per ride dropped 5.5% to $14.78 from June to mid-July

Public data from regulators in Chicago and New York City, two of the companies’ largest markets, shows a continued growth in trips and vehicles in recent months.

Several analysts said they expect rider demand to continue to outpace driver supply in the coming months.

Lyft, which reports after the bell on Tuesday, is expected to post an adjusted second-quarter EBITDA loss of nearly $50 million on revenue of $697 million, according to Refinitiv data. Analysts on average expect Uber, which reports after market close on Wednesday, to post a $319 million adjusted EBITDA loss on revenue of $3.7 billion.