"Despite this bullish supply agreement, we believe Saudi's decision likely reflects signs of weakening demand as lockdowns return," Goldman Sachs said in a note, although the investment bank maintained its year-end 2021 forecast for Brent of $65 a barrel.
ANZ Research said with US COVID-19 infections hitting new daily records, and restrictions tightening in Japan, pressure is growing on the Organization of the Petroleum Exporting Countries (OPEC), Russia and their allies, together called OPEC+.
The vaccine news helped offset fears from a sharp rise in coronavirus cases globally that has led to a string of renewed lockdowns, including strict measures in California, Germany and South Korea.