The World Health Organization (WHO) is warning vaccinated travellers should still be forced to quarantine over concerns about the spread of COVID-19.
It comes on a tragic day around the globe in which the UK recorded its highest number of daily cases yet.
As the world races to immunise, the WHO on Tuesday admitted it is unlikely vaccines will "eradicate" the coronavirus pandemic.
The agency also said there's no evidence vaccinated people cannot still spread the virus - which means, in the future, even people with the vaccine could be forced to quarantine for weeks after travelling.
It's been exactly one year since the WHO was first informed of the outbreak by China and Director-General Dr Tedros Adhanom reflected on what he said has been a difficult year for all countries.
"The WHO will not rest until those in need everywhere in all countries have access to the new vaccines and are protected."
Cases are currently increasing in the UK as temperatures drop, with a grim winter predicted.
Officials in Britain are calling it a 'New Year Crisis' as, for the first time, daily cases have surpassed 40,000. Doctors are overwhelmed and hospitals are at breaking point.
"We just don't have cubicles and trolleys for patients to go onto because we haven't managed to get patients up to a ward, because we don't have ward beds cause we don't have staff," hospital boss Dr Katherine Henderson said.
In Germany, mass vaccinations are off to a rocky start after workers in a care home were hospitalised having been injected with five times the recommended dose.
Meanwhile, Spain has announced it will keep a register of all people who refuse to be vaccinated.
And, like the UK, the US is bracing for a holiday surge in cases and is trying to increase its vaccination levels.
But at the same time, officials in New York are threatening million-dollar fines for anyone jumping the queue.
"If you violate the law on these vaccinations... you will be prosecuted," Governor Andrew Cuomo said.
