The World Health Organization (WHO) has granted emergency approval for a Covid vaccine made by Chinese state-owned company Sinopharm.
It is the first vaccine developed by a non-Western country to get WHO backing.
The vaccine has already been given to millions of people in China and elsewhere.
The WHO had previously only approved the vaccines made by Pfizer, AstraZeneca, Johnson & Johnson and Moderna.
But individual health regulators in various countries - especially poorer ones in Africa, Latin America and Asia - have approved Chinese jabs for emergency use.
With little data released internationally early on, the effectiveness of the various Chinese vaccines has long been uncertain.
But the WHO on Friday said it had validated the "safety, efficacy and quality" of the Sinopharm jab developed by the Beijing Institute of Biological Products.
The WHO said the addition of the vaccine had "the potential to rapidly accelerate Covid-19 vaccine access for countries seeking to protect health workers and populations at risk".
It is recommending that the vaccine be administered in two doses to those aged 18 and over.
A decision is expected in the coming days on another Chinese vaccine developed by Sinovac, while Russia's Sputnik vaccine is under assessment.
Why does WHO backing matter?
The green light from the global health body is a guideline for national regulators that a vaccine is safe and effective.
WHO director-general Tedros Adhanom Ghebreyesus said it would give countries "confidence to expedite their own regulatory approval".
It also means that the vaccine can be used in the global Covax programme, which was set up last year to try to ensure fair access to vaccines among rich and poor nations.
The decision to list the Chinese vaccine for emergency use is expected to give a substantial boost to the scheme, which has been struggling with supply problems.
In addition to China, countries already using the vaccine include the UAE, Pakistan and Hungary.
The decision on Friday to approve the vaccine for emergency use was made by the WHO's technical advisory group, which reviewed the latest clinical data and manufacturing practices.