Drugs giant AstraZeneca has revealed sales of its Covid-19 vaccine soared to 1.2 billion US dollars (£860 million) in the first half as the global jab programme rolled out at pace.

The group, which developed the jab with Oxford University, said vaccine sales more than tripled between the first and second quarters, rocketing from 275 million US dollars (£197 million) to 894 million US dollars (£640 million) in the three months to June 30.

It delivered about 319 million doses worldwide in the first half as the fight against Covid-19 picked up pace, but Astra pledged not to make a profit from the jab during the pandemic.

AstraZeneca supplied more than 80 million doses of the vaccination in the six months to more than 125 countries through the Covax global access initiative, making up more than 90% of Covax supply.

It also said that it had delayed application for approval of the jab in the US until the final six months of 2021, having originally hoped to put this through in the first half.

The group said that total half-year sales increased by 23% to 15.5 billion US dollars (£11.1 billion).

Without taking the Covid vaccine into account, sales rose 9% at constant currency to 14.4 billion US dollars (£10.3 billion).

AstraZeneca said that despite the sales boost, second quarter profits fell 20% to 764 million US dollars (£547 million), while earnings were 12% lower at 1.13 billion US dollars (£809 million).

Over the first half as a whole, pre-tax profits rose 25% to 2.4 billion US dollars (£1.7 billion), with operating profits 21% higher at 3 billion US dollars (£2.1 billion).

AstraZeneca upped its earnings outlook for the full-year following the completion this month of its 39 billion US dollar (£27.9 billion) deal to buy US drug company Alexion Pharmaceuticals.

It now expects total revenue to increase by a low-20s percentage this year thanks to the acquisition, excluding Covid vaccine sales.

The group has faced both praise and criticism during the pandemic, with its Covid jab hailed as being one of the first on the market and for its low cost in comparison to other jabs.

However, a controversy in Europe over suspected blood clotting led to the vaccine briefly being suspended, and some countries are still not rolling out the jab.