In the UK, 90-year-old Margaret Keenan has become the first person in the world to be given the Pfizer Covid-19 jab as part of a mass vaccination programme.
She received the first of 800,000 doses of the Pfizer/BioNTech vaccine that will be administered in the coming weeks.
It is expected that, by the end of December, up to four million more vaccines will have been administered, with hubs in the UK ready to vaccine the over-80s and some health and care workers.
After the UK’s Medicines & Healthcare Products Regulatory Agency (MHRA) approved the Pfizer/BioNTech vaccine for use last week, the UK has become the first country in the world to start administering the vaccine.
Some 50 hospitals around the UK have been administering the jab to patients and health workers this morning.
As a thrilled Health Secretary Matt Hancock suggested that Tuesday be called ‘V-day’, he continued to emphasise the importance of sticking to the rules and maintaining vigilance for the next few months.
While another four million doses are expected to be delivered to the UK by the end of December, most of the doses will not be available until next year.
In total, 40 million doses of the Pfizer/BioNTech vaccine have been ordered by the UK government, which is enough to vaccinate 20 million people, with two jabs needed per person.
While vaccination is not compulsory, Prime Minister Boris Johnson urged people to get the vaccine, saying it was "good for you and good for the whole country".
Appearing on BBC Breakfast, Prof Stephen Powis, national medical director of NHS England, said that vaccination was "one of the safest forms of medicine".
"This one has been tested in many thousands of people in clinical trials and, of course the independent regulator, the MHRA, has looked at it carefully – as it always does – and has given it the green light.
"And so if you get called, we'll be calling you to come and get it, then my advice is come and get it," he added.
People have been asked not to turn up at hospitals expecting to be vaccinated, but to wait to be notified.