Oil wavered as investors assess the potential for flagging Chinese demand against the expectation for shrinking global supplies.

Futures in New York gave back most of their earlier gains after U.S. equity markets opened Tuesday. A coronavirus flare-up in China is threatening fuel demand during the Lunar New Year period, with the government encouraging millions not to travel to prevent the outbreak from spreading further. Still, exports of Russia’s Urals crude are expected to decline next month and Iraq’s production will also dip.

Oil has surged almost 50% since the end of October but the rally has started to falter amid concerns about a sustained recovery in global fuel demand. Vaccine coverage won’t reach a point where it will stop the transmission of the virus in the foreseeable future, the World Health Organization said on Monday.

Prices have run up a lot, with the expectation that vaccinations and time are going to get rid of the Covid issue, said Michael Hiley, head of over-the-counter energy trading at New York-based LPS Futures. “We’ve had the move, now we have to wait for the actual event to happen.”

Brent’s prompt timespread was as much as 27 cents a barrel in backwardation—where near-dated contracts are more expensive than later-dated ones—compared with a 7-cent contango at the start of the month.

About 1.7 billion trips are expected across China over the Lunar New Year period, down 40% from 2019, although 15% higher than last year. The travel rush, which starts on Jan. 28 this year, runs for 40 days and is normally the biggest mass movement of people around the globe as hundred of millions of Chinese jump on planes, trains and automobiles to see their extended families.

In the U.S., analysts expect crude inventories rose last week, according to a Bloomberg survey. The industry-funded American Petroleum Institute will report its figures later Tuesday ahead of a U.S. government tally on Wednesday.