Production cuts and inventory reductions were the primary reason for higher oil prices over the last few months but now an economic recovery and a resulting increase in demand will be key to continued price gains, said Fitch Ratings on Thursday.

In a new report, the rating agency said global oil demand could decline in the first quarter of 2021, amid the resumption of public health restrictions in a number of countries.

Even so, demand remains well above the levels of last spring, Fitch noted.

As well, recent production cuts should decrease the risk of oversupply, even with renewed lockdowns, said the ratings agency.

Looking further out, the key to stronger demand and higher prices will be dependent on Covid-19 vaccine distribution and its effect on the underlying recovery, Fitch said.

“The positive effects of vaccination programmes on the oil demand recovery may not be visible for several months until a critical mass of population is inoculated,” the report said.

“Mass vaccination is likely to lead to a sustainable improvement in oil demand,” Fitch added, “although there is some uncertainty about vaccines’ effectiveness against the most recent virus mutations.”

Additionally, a change in U.S. policy toward Iran could increase oil supply in the months ahead.

“Although significant excess inventories were consumed in the second half of 2020, oil volumes in storage remain high,” said Fitch. “Furthermore, there is huge unused production capacity in the market, mainly represented by Saudi Arabia, but also by Iran, which is subject to U.S. sanctions.”