In its statement on 25 March the company said the latest analysis confirms “vaccine efficacy consistent with the pr-specified interim analysis” announced earlier in the week.
The firm said its vaccine also has 100 per cent efficacy against severe or critical disease and hospitalisation due to coronavirus, and is 85 per cent effective against symptomatic Covid-19 in patients aged 65 years and over.
Analysis showed 190 symptomatic cases of the illness from the 32,449 trial participants, with the company saying that 76 per cent efficacy was observed 15 days or more after two doses of its shot were given four weeks apart.
Phase three of the trial of the vaccine, which has been the subject of controversy in Europe over concerns about links to very rare blood clots, included participants across all age groups in the US, Chile and Peru.
AstraZeneca hopes the jab will protect against severe disease from all coronavirus variants, with the European Medicines Agency, the World Health Organisation and the Medicines and Healthcare products Regulatory Agency (MHRA) all having declared it safe and effective.
Vaccine ‘highly effective in adults’
AstraZeneca’s Mene Pangalos, executive vice president of biopharmaceutical research and development, said: “The primary analysis is consistent with our previously released interim analysis, and confirms that our Covid-19 vaccine is highly effective in adults, including those aged 65 years and over.”
The revised figures come after the company, which developed the jab with the University of Oxford, was forced to defend its use of vaccine data due to US authorities suggesting some results may not be the most up to date.
The US Data and Safety Monitoring Board said in a statement earlier this week that initial AstraZeneca figures released on Monday were based on “outdated information”, and that the company may have provided an incomplete view of the efficacy data.
“We look forward to filing our regulatory submission for Emergency Use Authorisation in the US and preparing for the rollout of millions of doses across America,” said Pangalos on the updated analysis.
AstraZeneca said on Thursday the trial’s results had been presented to the board and would be the basis for a regulatory submission for emergency use to the US Food and Drug Administration in coming weeks.
Oxford is currently carrying out a clinical trial on children to test the safety and efficacy of the shot in younger age groups, with initial results expected in the summer.
‘Blockade’ on vaccines ‘damaging’
The revised findings come amid production delays and a diplomatic dispute between the UK and the EU over supplies of the Oxford/AstraZeneca vaccine.
EU leaders are set to discuss proposals aimed at tightening restrictions on vaccine exports at a virtual European Council summit today (25 March), after London and Brussels moved to calm tensions following weeks of ramped up rhetoric.
A joint statement said the two sides were seeking a “win-win” deal to increase supplies across the UK and EU as the bloc’s dispute with AstraZeneca continued.
The European Commission has set out a tougher regime to stem supplies of jabs to nations faring better in the pandemic as the bloc’s states face a third wave of cases.
The move could result in supplies of vaccines from the EU to the UK being blocked unless shipments of AstraZeneca jabs also travel from Britain to the continent.
Boris Johnson warned that a “blockade” on vaccines could result in “long-term” damage but said he continued to work with his European partners.