A Covid vaccine developed by the University of Oxford and AstraZeneca has proved to be 70% effective after a large-scale trial.

New data shows the coronavirus jab, which had trials in the UK and Brazil, had positive high-level results from an interim analysis of the trials. 

Developers say no hospitalisations or severe cases of the disease were reported in participants receiving the vaccine.

The UK has placed orders for 100 million doses of the Oxford vaccine – enough to vaccinate most of the population – with rollout expected in the coming weeks if the jab is approved.

It also has orders for 40 million doses of a jab from Pfizer and BioNTech, which has been shown to be 95% effective.

Another jab from Moderna is 95% effective, according to trial data.

Professor Andrew Pollard, chief investigator of the Oxford Vaccine Trial at Oxford, said: “These findings show that we have an effective vaccine that will save many lives.

"Excitingly, we’ve found that one of our dosing regimens may be around 90% effective and if this dosing regime is used, more people could be vaccinated with planned vaccine supply.

"Today’s announcement is only possible thanks  to  the  many  volunteers  in  our  trial,  and  the  hard-working  and  talented  team  of  researchers based around the world.”

Pascal Soriot, chief executive officer at AstraZeneca, said: “Today marks an important milestone in our fight against the pandemic.

"This vaccine’s efficacy and safety confirm that it will be highly effective against COVID-19 and will have an immediate impact on this public health emergency.

"Furthermore, the vaccine’s simple supply chain and our no-profit pledge and commitment to broad, equitable and timely access means it will be affordable and globally available, supplying hundreds of millions of doses on approval.”