* UK says it wants the vaccines it has ordered
* EU set to require authorisation for vaccine exports
* French vaccination centres cancel appointments
* WHO: vaccine makers working non-stop to plug supply
* AstraZeneca CEO: EU was late to do a deal (Recasts)
By Paul Sandle and Philip Blenkinsop
LONDON/BRUSSELS, Jan 28 (Reuters) - Europe's fight to secure COVID-19 vaccine supplies intensified on Thursday when the European Union said it would tighten oversight of exports after a row with AstraZeneca and Britain demanded that it receive all the shots it paid for.
The EU, whose member states are far behind Israel, the United Kingdom and the United States in rolling out vaccines, is scrambling to get supplies just as the West's biggest drugmakers slow deliveries to the bloc due to production problems.
As vaccination centres in Germany and France cancelled or delayed appointments, the EU publicly rebuked Anglo-Swedish drugmaker AstraZeneca for failing to deliver and even asked if it could divert supplies from Britain.
The EU Commission, which has coordinated vaccine orders, said it would on Friday detail a mechanism to require both notification and authorisation of COVID-19 vaccine exports from the bloc.
Britain, which has repeatedly touted its lead in the vaccine rollout race since leaving the EU's orbit on Jan. 1, said its deliveries must be honoured.
"I think we need to make sure that the vaccine supply that has been bought and paid for, procured for those in the UK, is delivered," Minister for the Cabinet Office Michael Gove told LBC Radio.
Asked if the British government would prevent AstraZeneca diverting essential vaccine supplies from Britain to the EU, Gove said the crucial thing was that Britain received its orders as planned and on time.
Under fire from the EU, AstraZeneca CEO Pascal Soriot said the EU was late to strike a supply contract so the company did not have enough time to iron out production problems at a vaccine factory run by a partner in Belgium.
The swiftest mass vaccination drive in history is stoking tensions across the world as big powers buy up doses in bulk and poorer nations try to navigate a financial and diplomatic minefield to collect whatever supplies are left.
The EU scolded AstraZeneca on Wednesday and demanded the drugmaker spell out how it would supply the bloc with reserved doses of COVID-19 vaccine from plants in Europe and Britain.
Tensions have risen as both New York-based Pfizer and AstraZeneca, headquartered in Cambridge, England, have had production problems.
AstraZeneca's Soriot told Italy's La Repubblica the problem concerned manufacturing the vaccine itself - specifically the yield of cell cultures and filtering of the vaccine.
He said there had been similar issues in the UK supply chain, but the UK contract was signed three months before the European deal, so there was an extra three months to fix the glitches.
"The reality is there is a shortage of vaccines," the World Health Organization's Europe director, Hans Kluge, said.
"Manufacturers and producers are working 24-7 to bridge the gaps and we're confident the delays we are seeing now are going to be made up by extra production in the future."
Israel is by far the world leader on vaccine rollout per head of population, followed by the United Arab Emirates, the United Kingdom, Bahrain and the United States. Behind them are Italy, Germany, France, China and Russia.
Britain has injected 7.1 million first doses of vaccines into arms, and is on track to deliver a shot to all over-70s, frontline medics and care workers, the clinically vulnerable and older care home residents - some 15 million people - by Feb. 15.
In the northern French region of Hauts-de-France, France's second-most-densely-populated region, several vaccination centres were no longer taking appointments for a first jab. In several other French regions, some online appointment platforms closed booking options.
Spain's Madrid region has ceased first vaccinations for at least this week and next and was using the few doses it has to administer second shots to those who have had the first one, said deputy regional government chief Ignacio Aguado.
Germany's most populous state, North Rhine-Westphalia, last week postponed opening its vaccination centres until Feb. 8, while the state of Brandenburg has also had to push back vaccination appointments originally scheduled for the end of January due to delivery delays.
Germany's top-selling Bild newspaper described the problems around procuring vaccines as a "scandal".
(Reporting by Emma Thomasson and Paul Carrel in Berlin and Matthias Blamont in Paris and Kate Holton in London; writing by Guy Faulconbridge; editing by Keith Weir and Nick Macfie)
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