Britain has begun the mass vaccination of its population against COVID-19, becoming the first Western nation to do so in a global endeavour that poses one of the biggest logistical challenges in peacetime history.

On a day dubbed “V-Day”, health workers started inoculating people on Tuesday with a shot developed by Pfizer and BioNTech, with the country a test case for the world as it contends with distributing a compound that must be stored at -70 degrees Celsius.

Britain is the first country globally to begin mass inoculations with that vaccine, one of three shots that have reported successful results from large trials after being developed in record time.

Margaret Keenan, a 90-year-old grandmother, was the first person in the world to receive the vaccine outside of a trial following its rapid clinical approval.

90-year-old Margaret Keenan is the first to receive the Pfizer/BioNTech vaccine, administered by Matron May Parsons, as UK's mass vaccination programme begins https://t.co/3eBGv3RUsU pic.twitter.com/ltWAL8uDmr

— BBC Breaking News (@BBCBreaking) December 8, 2020

Keenan received the vaccine at her local hospital in Coventry, central England, on Tuesday morning, a week before she turns 91.

“I feel so privileged to be the first person vaccinated against COVID-19,” she said.

“It’s the best early birthday present I could wish for because it means I can finally look forward to spending time with my family and friends in the New Year after being on my own for most of the year.”

Health Minister Matt Hancock described the start of vaccinations as “V-Day”.

“If we manage to do that for everybody who is vulnerable to this disease, then we can move on and we can return to normal,” he said.

The launch will fuel hope that the world may be turning a corner in the fight against a pandemic that has killed more than 1.5 million people and crushed economies.

Britain, the worst-hit European country with more than 61,000 deaths, has ordered enough supplies of the Pfizer-BioNTech shot to vaccinate 20 million people.

The developers said it was 95 per cent effective in preventing illness in final-stage trials.

Russia and China have both already started giving domestically produced vaccine candidates to their populations, though before final safety and efficacy trials have been completed.

Today the first vaccinations in the UK against COVID-19 begin. Thank you to our NHS, to all of the scientists who worked so hard to develop this vaccine, to all the volunteers – and to everyone who has been following the rules to protect others. We will beat this together. https://t.co/poOYG1vHQe

— Boris Johnson (@BorisJohnson) December 8, 2020

In Britain, about 800,000 doses are expected to be available within the first week, with care home residents and carers, the over-80s and some health service workers prioritised.

The logistical challenges in distributing the vaccine, which only lasts five days in a regular fridge, mean it will first go to dozens of hospitals and cannot yet be taken into care homes.

Transport and distribution could prove more challenging in bigger countries, including the US and India which have been worst-hit by the pandemic, and in hotter nations.

Another vaccine to have had trial success, developed by AstraZeneca and Oxford University, is viewed as offering one of the best hopes for many developing countries because it is cheaper and can be transported at normal fridge temperatures.

Late-stage trials found it had an average success rate of 70 per cent.

“The deployment of this vaccine marks a decisive turning point in the battle with the pandemic,” said Simon Stevens, head of the publicly funded National Health Service.

In total Britain has ordered 40 million doses of the Pfizer/BioNTech shot. As each person requires two doses, that is enough to vaccinate 20 million people in the country of 67 million.

But the country is spreading it bets and has ordered 357 million doses of seven different COVID-19 vaccines in all.

-AAP