Oil declined on Monday, after earlier rising to $52 a barrel, as optimism over the U.S. stimulus package and the start of a European vaccination campaign was counteracted by weak demand and the prospect of higher OPEC+ output. After U.S. President Donald Trump backed down from a threat to block the $2.3 trillion package, Democrats on Monday will try to push through larger $2,000 relief payments. Europe on Sunday launched a mass COVID-19 vaccination drive.

Brent Crude fell 43 cents, or 0.84%, to settle at $50.86 per barrel, after trading as high as $52.02 earlier in the session. U.S. WTI Crude settled 61 cents, or 1.26%, lower at $47.62 per barrel. “The signing of the U.S. stimulus bill, with the possibility of an increased size, should put a floor under oil prices in a shortened week,” said Jeffrey Halley, analyst at broker OANDA. Oil has recovered from historic lows hit this year as the pandemic hammered demand. Brent reached $52.48 on Dec. 18, its highest since March. But the emergence of a new variant of the virus has led to movement restrictions being reimposed, hitting near-term demand and weighing on prices.

Oil remains vulnerable to any further setbacks in efforts to control the virus, said Stephen Innes, chief global market strategist at Axi, in a note. Also coming into focus will be a Jan. 4 meeting of the Organization of the Petroleum Exporting Countries and allies, a group known as OPEC+. The group is tapering record oil output cuts made this year to support the market. OPEC+ is set to boost output by 500,000 barrels per day in January and Russia supports another increase of the same amount in February.