As AstraZeneca’s top managers held a virtual meeting on January 25, they were interrupted by breaking news. Germany’s Handelsblatt newspaper reported that the company’s Covid-19 vaccine — seen as one of the world’s best hopes for conquering coronavirus — was largely ineffective in people aged over 65. The shocked pharma executives scrambled to get in touch with their development partners at Oxford university before issuing an unusually emphatic denial: the claim was “completely incorrect”.

Official data published several days later helped to further undermine the article, but its central assertion — attributed to German officials — was ominous evidence of worsening trouble with the EU. Since mid-January when AstraZeneca told the pandemic-ravaged bloc it would be unable to deliver the expected volumes of vaccine, the relationship with the EU has been badly damaged. As it prepares to publish new data in the US, which is yet to approve the vaccine, the drugmaker also faces further scrutiny in the world’s largest pharmaceutical market.

AstraZeneca must now defend itself against two separate charges: that its clinical trial data is weak and manufacturing inadequate. Meanwhile, the EU has found itself in the unusual position of demanding more of a vaccine that some member states believe may not work in the elderly.

An endeavour that started with impeccable intentions — to bring a low-cost vaccine to the world without profit — has harmed one of the pharmaceutical industry’s star performers. This account of a turbulent period for the Anglo-Swedish company is based on interviews with more than 30 executives, scientists and government officials in the UK, US and EU.