That means that just one in 10 people will be able to be protected from Covid-19 next year. And that's even if a vaccine can be approved as safe at the beginning of 2021.
A key issue is that seven of the nine vaccines in late-stage trials require two doses. That factor means just over 12 per cent of the 7.8 billion people who need it will be immunised.
The Coalition for Epidemic Preparedness Innovations estimates that even if manufacturing capacity doubles, less than half the world's population could be protected by the end of 2022.
It is not good news for people hoping for some offshore travel - even close-to-home trips - and may mean further adjustment to people's mindsets on the pandemic.
Last week, Australian Prime Minister Scott Morrison revived the idea of the grounded transtasman bubble.
He suggested it could work between regions with no known outbreaks, meaning some Kiwis would be able to visit Australia without a quarantine. About 15 per cent of returning Australians had come from New Zealand.
"For example, the whole of the South Island, that's an area where there is no Covid," Morrison said.
"So if we could get to a situation soon where those coming home from New Zealand are able to enter Australia without going into a 14-day quarantine… we see that as another way of enabling more and more Australians to come home."
But Air New Zealand chief executive Greg Foran said on Sunday that quarantine-free travel across the ditch is unlikely to begin before March and "could well be longer".
Foran also cited vaccine issues - the slow distribution, possible limited effectiveness and public safety fears - as reasons why it will take some time for air travel to recover.
A new Pew Research Centre poll in the United States shows public confidence in taking a vaccine has fallen since May. Now, 51 per cent of those surveyed would definitely or probably take a shot compared to 72 per cent four months ago.
Some favourite destinations for Kiwis in Europe are seeing a second wave of infections as the Northern Hemisphere heads towards winter.
A European Union list of countries' cases per 100,000 people in the past two weeks has Spain and France at the top. England will soon introduce a new legal requirement - backed up with fines - for people to self-isolate if they test positive or are a close contact.
But there is progress on rapid testing which could help smooth travel eventually.
A DnaNudge rapid test can accurately diagnose a coronavirus infection within 90 minutes without a specialist lab. An Imperial College London study showed it gave similar results to current tests. The device can perform 16 tests a day.
In Canada, a saline gargle spit test for schoolchildren is being trialled in British Columbia.
Italy is using a test originally developed in South Korea that delivers results in less than 30 minutes and works as a quick screener. People arriving at Rome's main airport from high-risk countries are sent to a Covid-19 test centre. Anyone who tests positive is isolated and given a full lab test.
Global air travellers are soon likely to need such a test before they board planes on their trips. It is a necessary step to bringing overseas travel closer to reality for people around the world.
