EU leaders will discuss by video conference how to protect their 450 million citizens from new, more contagious variants of the coronavirus, ensure stable vaccine deliveries, ramp up production and update jabs to counter new strains.

Two officials with the bloc’s executive European Commission estimated that around 400 million doses of “ghost” vaccine had been offered by fraudsters at a price of up to €3 billion.

“There is a really large quantity,” one said.

“Nobody has any idea what is actually in these vials … the best case is it’s just not working, in the worst case it’s a very serious issue.”

The official, who noted that most of the shots offered to EU governments by traders were purportedly the AstraZeneca vaccine, compared the situation to the start of the coronavirus pandemic in early 2020 when criminals exploited a shortage of masks and other protective equipment.

A second official, who also spoke on condition of anonymity, said the Commission was worried about “ghost” vaccines.

“It is unclear whether these are genuine vaccine doses or if we are just talking about salt water in small vials,” the official told Reuters.

The EU had warned already that vaccine fraud was on the rise, with fake doses circulating on the market, but the extent of the problem has been unclear until now.