Reuters reports that European Central Bank policymaker Pablo Hernandez de Cos said that it will take time before any COVID-19 vaccine has a positive impact on the economy. 

New restrictions imposed in euro zone countries to curb the second wave of the pandemic mean that the ECB's upcoming macroeconomic projections in December would be most likely revised downwards, de Cos added.

"The vaccine is very positive news, regarding investor confidence, consumers confidence and economic activity. But I would like to be cautious. In the short term, restrictions will continue across Europe," de Cos said.

The good news on the vaccine "will take time to translate into economic activity," he added.