Here’s some sobering news: The International Energy Agency has once again downgraded its forecast for 2021, saying that it will take months for coronavirus vaccines to start reversing the damage caused by the pandemic.

The agency on Tuesday knocked 170,000 barrels per day off its demand forecast for next year because of weaker than expected purchases of jet fuel and kerosene.

“The understandable euphoria around the start of vaccination programmes partly explains higher prices but it will be several months before we reach a critical mass of vaccinated, economically active people and thus see an impact on oil demand,” the IEA said in its monthly report.

“In the meantime, the end of year holiday season will soon be upon us with the risk of another surge in Covid-19 cases and the possibility of yet more confinement measures,” it added.

Expectations for oil demand are important because they tell a story about the broader economy. If planes are grounded and people are staying home, they consume less energy. The IEA, which monitors energy market trends for the world’s richest countries, is trying to answer the same basic question as investors: How quickly will vaccines help?

The sight of health care workers in the United States receiving the vaccination on Monday was a genuine moment for celebration. At the same time, the virus is surging across key economies and forcing politicians to impose new lockdowns that could send their countries back into recession.

“Yesterday marked an important milestone in the US as the first members of the public began to get the Pfizer/BioNTech vaccine following its approval,” Deutsche Bank analysts wrote in a research note. “However, the broader theme across the world was how the authorities were having to tighten restrictions further given the rising caseload ahead of Christmas.”

Some updates:

  • New York City is shutting down indoor dining for at least two weeks.
  • London faces tighter restrictions starting on Wednesday, with bars and pubs closed except for takeaway orders.
  • Germany and the Netherlands are going into “hard” lockdowns that will extend beyond Christmas, and the Italian government is considering new measures to curb the virus.
  • On the other side of the world, Japan now has the highest number of Covid-19 patients in intensive care since the pandemic began.
  • South Korea recorded 880 new coronavirus cases on Monday, and the government is weighing up whether to introduce the highest level of coronavirus restrictions.

The trends leave the IEA preaching caution, and warning of a possible third wave.

“Our central assumption is that vaccines will be introduced in OECD countries in 1Q21 and widely administered in 2Q21 and 3Q21, thus allowing many activities to progressively return to normal,” the agency warned in its report.

“However, considerable uncertainty remains about vaccines’ efficacy, availability, and deployment. It is possible that, after the upcoming holiday season, a third wave of the virus will affect Europe and other parts of the world before vaccines have time to take effect,” it added.