Drugs giant AstraZeneca has said it is on track to develop a Covid-19 vaccine against new strains of the disease by the autumn as it revealed its annual profits have more than doubled.

The group is aiming to start clinical trials for its new jab in the spring so that vaccination programmes can begin before next winter.

It is cutting the time needed to reach production at scale to between six and nine months, it added.

Chief executive Pascal Soriot said the company’s current vaccine is thought to provide a “good level of protection” against severe disease caused by the new variants, such as the Kent and South African strains, but will need to be adapted to prevent milder symptoms.

The announcement came as the company reported pre-tax profits of 3.92 billion US dollars (£2.83 billion) for 2020 as the success of new medicines saw total sales hit 27 billion US dollars (£19.5 billion) – a rise of 10%.

The profits haul marks a significant rise on the 1.55 billion US dollars (£1.12 billion) seen in 2019, despite AstraZeneca offering its coronavirus jab on a not-for-profit basis.

But the vaccine helped boost revenues over the year, contributing 2 million US dollars (£1.44 million) to total turnover.

AstraZeneca said it is set to deliver 100 million doses of its current vaccine globally in February, doubling to 200 million a month by April.

Mr Soriot said the UK should start seeing a decline in hospital admissions from the disease “very soon”, with the Government’s rapid vaccination programme expected to start having a marked impact from March.

The AstraZeneca/Oxford vaccine team were given a boost on Wednesday when scientists advising the World Health Organisation (WHO) recommended the use of the jab in all adults.

We’re going to save thousands of lives and that’s why we come to work every day

It came after a number of countries opted not to give the jab to those over the age of 65.

The vaccine developers have come under pressure recently, in particular over supply issues in the European Union.

Mr Soriot said it is important not to lose sight of the “big picture”.

“One hundred million doses in February means 100 million vaccinations, which means hundreds of thousands of severe infections avoided and it also means thousands of deaths that are avoided,” he said.

“We’re going to save thousands of lives and that’s why we come to work every day as individuals.”

AstraZeneca’s fourth-quarter profits rocketed to 1.17 billion US dollars (£850 million) from 240 million US dollars (£173 million) a year ago as sales reached a record 7 billion US dollars (£5.06 billion).

The firm hiked its 2021 sales outlook, revealing it now expects to deliver revenue growth in the “low-teens” percentage.

But it stressed that the guidance does not include any sales or profit impact from the coronavirus jab or its planned takeover of US group Alexion Pharmaceuticals.

Sebastian Skeet, senior analyst at Third Bridge, said: “On a human level, AstraZeneca’s vaccine saga has been disappointing – the clash with the EU, new data demonstrating a lack of efficacy in preventing mild to moderate infection caused by the South African variant, and the decision by German authorities to limit vaccinations in persons under 65 years old.

“However, the opposite can be said for AstraZeneca’s core business. The company is arguably the poster child for big pharma turnarounds, with CEO Pascal Soriot rebuilding the pipeline and establishing the necessary growth drivers.”