Many nations, travel firms and medical organisations are giving plenty of thought to the near future of travel and how a coronavirus vaccine may help to ease restrictions and increase confidence among travellers.
These are some of the key questions.
If I get Covid jabs, will that make me immune or just reduce symptoms?
That is one of many issues that is not clear. Every county wants to know whether a prospective traveller’s vaccination means that their population will not be put at risk by the visitor.
At present, there is no clarity about the extent to which any of the vaccines under development provides immunity against coronavirus, rather than simply limiting the worst effects of Covid-19 on the individual.
If it is the latter, health authorities around the world will want to understand if the suppression of symptoms also reduces or eliminates the risk of transmission from the individual.
If and when that judgment is made, the next step is for medical opinion to coalesce around the certification that will be internationally recognised. This has long been the case for longer-established vaccinations, notably Yellow Fever.
Unfortunately the confusion and conflict so far seen globally about opening up travel after coronavirus suggests it may not happen swiftly.
Meanwhile, it may be that as a halfway measure, individual countries will allow some sort of evidence of a vaccination as an alternative to testing and/or quarantine.
What happens if I have already had a vaccine or am in line for one soon?
Thousands of people have had jabs as part of the trials, but these are of no significance for the purposes of certification.
The health secretary, Matt Hancock, has indicated that the UK vaccination programme could begin in December. But some of the early recipients of a vaccine could be at a disadvantage if they get the jab ahead of agreement on the appropriate certificate.
They might even find they need a second vaccine in order to acquire the evidence of immunity that other countries demand.
Will travellers be able to jump the queue for vaccination?
Some health professionals have mooted that occupation should also be an indicator of priority, arguing that if someone is obliged to travel abroad frequently then they should be ahead of the general, low-risk population because the vaccine would be especially valuable.
More widely, it is likely that some private organisations will source coronavirus vaccines specifically for travellers who need or want a jab in order to go abroad. If this happens to the detriment of people in high-risk groups, it will prove a highly controversial option.
Will I need a vaccination certificate to board a plane?
In the absence of a widely available and proven vaccine, no airline nor destination country can make any such demand. But the boss of Qantas has said they will be needed in time.
After positive news about three different coronavirus vaccines, Alan Joyce, the chief executive of the Australian airline, predicted that his airline would make evidence of vaccination mandatory on longer flights.
Mr Joyce told the Australian programme A Current Affair: “We are looking at changing our terms and conditions to say that, for international travellers, we will ask people to have a vaccination before they get on the aircraft.
“Certainly, for international visitors coming out [of Australia] and people leaving the country, we think that's a necessity.”
But Michael O’Leary, chief executive of Ryanair, said in response: “Qantas is specifically talking about 12-14 hour long-haul flights. They’re not talking about it for their domestic Australian flights, for example.
“You will not require vaccines to travel on short-haul flights between Ireland and the UK or between the UK and Spain, Portugal or Greece next year.”
But the Ryanair boss said the existence of a vaccine will increase travellers’ confidence.
“We think the vaccine will remove the ability of governments to lock people down, it removes the risk of the health service being overwhelmed, and we think it will create – certainly by the summer of 2021 – a return to families travelling on much-needed holidays, certainly within Europe,” he told the BBC Today programme.
And elsewhere in travel?
Cruise lines could be among the very early adopters of a mandatory vaccine requirement as they seek safely to resume voyages.
They face a mass of problems arising from the coronavirus pandemic, and demanding passenger present evidence of a vaccination could solve many of them – as well as giving extra confidence to other travellers, especially those in the risk categories.
Given the predominantly older clientele associated with cruising, it may be that a substantial number of prospective passengers are vaccinated relatively early in the programme.
Some more extreme adventure operators could also make vaccination a stipulation, given the potentially severe implications of an outbreak on a remote island, a mountain range or a polar region.
I tested positive for Covid 19 a month ago. Does that mean I am immune, and can I use it in lieu of a vaccine?
In time, once more is known about the virus – and whether previous infection provides valuable immunity – it may be that a blood test confirming that an individual has contracted coronavirus provides an acceptable alternative. But that is years rather than months away.