British travellers vaccinated in the UK were denied a holiday to Malta because they received the Indian-made version of the AstraZeneca shot.
Steve and Glenda Hardy were stopped at a UK airport because their doses of the shot were not made at an EU-approved manufacturing site.
The vaccine is the same one used in Europe but has not been authorised by the EU, triggering an outcry from developing countries.
Doses of the Indian-made shot, known as Covishield, have been shipped around the world under the Covax scheme – and also exported to Britain.
UK Prime Minister Boris Johnson said he was confident the technicality would not pose a problem for British travellers.
But Mr and Mrs Hardy, aged 64 and 63, were denied the chance to see their son for the first time since he moved to Malta a year ago.
“We were just gutted,” Mrs Hardy told the Daily Telegraph after the couple were turned back at Manchester Airport in north-west England.
“We thought we’d covered ourselves – we paid for PCR tests, downloaded the NHS app and printed off the letter – but we fell at the final hurdle.”
Mrs Hardy said that at least three others were turned away from the flight after the airline checked the batch numbers of their vaccines.
She said she felt let down by the UK government following Mr Johnson’s promise that it would not be a problem.
The UK’s Department of Health said this month that all AstraZeneca vaccines would appear identically on the digital app.
But the batch number is displayed on the app. The batches 4120Z001, 4120Z002 and 4120Z003 were manufactured by the Serum Institute of India.
Prof Adam Finn, a member of the UK government’s vaccine committee, said "people should be reassured who’ve received these batches that they’ve received exactly the same stuff".
Brussels blames the controversy on the Serum Institute’s failure to submit a separate application for its vaccine.
But critics say the EU’s stance risks creating a two-tier system and fostering anger in developing countries.
The EU is a major donor to Covax, which has distributed millions of AstraZeneca doses that were made in India under the brand name Covishield.
The vaccine is listed for emergency use by the World Health Organisation, but is yet to be authorised by the European Medicines Agency (EMA).
The EMA approved the AstraZeneca shot in January but says EU inspectors need to approve the manufacturing sites in India before Covishield is cleared.
It means that EU countries are not obliged to accept travellers vaccinated with Covishield, although individual governments may choose to do so.
While some countries say they will accept Covishield, Malta is one of about a dozen nations yet to recognise it.