The World Health Organisation (WHO) has said it would be in the interest of richer nations to ensure that any vaccines eventually produced to protect against the new coronavirus were shared globally.
"Vaccine nationalism is not good, it will not help us," said the UN health agency's chief Tedros Adhanom Ghebreyesus during the Aspen Security Forum in the United States, via video-link from the WHO's headquarters in Geneva, reports Al Jazeera citing news agencies.
"For the world to recover faster, it has to recover together, because it's a globalised world: the economies are intertwined. Part of the world or a few countries cannot be a safe haven and recover."
He said the existence of the deadly respiratory disease anywhere puts lives and livelihoods at risk everywhere.
"The damage from COVID-19 could be less when those countries who ... have the funding commit to this."
"They are not giving charity to others: they are doing it for themselves, because when the rest of the world recovers and opens up, they also benefit."
The WHO also said that multiple types of vaccines would likely be needed to combat COVID-19.
Some 26 candidate vaccines are in various stages of being tested on humans, with six having reached Phase 3 wider levels of testing.
"Phase 3 doesn't mean nearly there," explained the WHO's emergencies director Michael Ryan.
"Phase 3 means this is the first time this vaccine has been put into the general population, into otherwise healthy individuals, to see if the vaccine will protect them against natural infection.
"We've got a good range of products across a number of different platforms, across a number of different countries," he said of the leading candidate vaccines, which use different methods to provide immunity.
However, "there's no guarantee that any of these six will give us the answer, and we probably will need more than one vaccine to do this job".