Oil prices remained generally constant on Thursday, as signals that the worst effects of the Omicron coronavirus variety may be reasonably contained were offset by new restrictions in response to the virus's soaring case count.

At 1109 GMT, Brent crude futures were up 19 cents, or 0.3 percent, to $75.48 a barrel, following a 1.8 percent gain the previous session.

The United States West Texas Intermediate (WTI) crude futures were up 5 cents, or 0.1 percent, at $72.81 a barrel, following a 2.3 percent gain in the previous session.

Wednesday's significant gains were aided in part by a larger-than-expected decrease in US crude stockpiles last week.

Additionally, the United States approved Pfizer Inc's COVID-19 antiviral pill for adults aged 12 and older, making it the first oral and at-home treatment as well as a new tool against the rapidly spreading Omicron strain.

Meanwhile, AstraZeneca stated that a three-dose course of its COVID-19 vaccination is effective against the Omicron form, citing laboratory results from Oxford University.

On the other hand, governments reinstated various restrictions to stymie Omicron's spread.

The Chinese city of Xian ordered its 13 million citizens to remain at home on Wednesday. At the same time, Scotland imposed gathering restrictions beginning Dec. 26 and lasted up to three weeks, and two Australian states reinstated mask regulations.

However, concerns about the potential impact of mobility limitations on fuel consumption have subsided, as the Organization of the Petroleum Exporting Countries (OPEC), Russia, and allies left the door open to revising their January supply addition plan of 400,000 barrels per day.