Pfizer raised the price of its COVID-19 vaccine by more than a quarter and Moderna by more than a tenth in the latest EU supply contracts as Europe battled supply disruptions and concerns about side effects from rival products, writes the Financial Times.

The groups are set to generate tens of billions of dollars in revenue this year as they sign new deals with countries anxious to secure supplies for potential booster shots in the face of the spread of the highly infectious Delta variant.

The terms of the deals, struck this year for a total of up to 2.1bn shots until 2023, were renegotiated after phase 3 trial data showed their messenger ribonucleic acid vaccines had higher efficacy rates than cheaper shots developed by Oxford/AstraZeneca and Johnson & Johnson.

The new price for a Pfizer shot was €19.50 against €15.50 previously, according to portions of the contracts seen by the Financial Times.

The price of a Moderna jab was $25.50 a dose, the contracts show, up from what people familiar with the matter said was about €19 ($22.60) in the first procurement deal but lower than a previously agreed $28.50 because the order had grown, according to one official close to the negotiations.