By Guy Faulconbridge and Kate Holton
LONDON (Reuters) -Britain began using Moderna's COVID-19 vaccine on Wednesday in Wales just as its rollout of other shots fell to their lowest level this year due to a supply crunch caused by manufacturing problems at AstraZeneca (NASDAQ:AZN).
Britain has surged ahead of the rest of Europe in the race to vaccinate its population, with almost half of its citizens receiving a first dose. But supply issues from its main Oxford-AstraZeneca shot have slowed progress in recent days.
Britain distributed almost 96,000 shots on Sunday and just over 105,000 on Monday, the lowest figures since the government started publishing daily numbers in January.
It had warned that the rollout would slow in April due to AstraZeneca's manufacturing issues, including at a site in India.
A spokesman for Prime Minister Boris Johnson said that he would not go into details about supply and delivery timelines but said the country remained on track to provide a first dose to all adults by the end of July.
That rollout will now be bolstered by the addition of the Moderna shot. Already used in the United States and other parts of Europe, it becomes the third vaccine to be used in Britain after AstraZeneca and one from Pfizer-BioNTech.
Elle Taylor, 24, said she was delighted to be the first person in the United Kingdom to receive the Moderna shot in Carmarthen, Wales.
"I'm an unpaid carer for my grandmother so it is very important to me that I get it, so I can care for her properly and safely," she told reporters.
Johnson welcomed the arrival. "We have ordered 17 million doses that will be going into arms across the UK in the coming weeks," he said on Twitter.
"Please get your jab as soon as you are contacted."
Moderna uses the same mRNA technology as Pfizer (NYSE:PFE)'s shots but can be stored at normal fridge temperatures unlike its rival U.S. vaccine, which must be kept and shipped at ultra-low temperatures.
The shot is expected to be used in the rest of the United Kingdom by the middle of April.
The UK has vaccinated 31.6 million people with a first dose of a COVID-19 vaccine - and administered 5.5 million second doses. In recent weeks, cases, hospitalisations and deaths have all fallen.
Israel is the world leader in vaccinating its population against COVID-19, followed by the United Arab Emirates, Chile, the United Kingdom, the United States, Bahrain, Serbia and Hungary, according to Our World in Data.