Serum Institute CEO Adar Poonawalla tweeted Monday to reassure Covishield-vaccinated Indians facing issues with travel to Europe in light of the EU's new 'vaccine passport' scheme, which does not yet recognise the India-made version of the AstraZeneca-Oxford University vaccine. Mr Poonawalla said he had "taken this up at the highest levels... with regulators and diplomatic" and that he hoped the matter would be resolved soon.