The Oxford / AstraZeneca surge offers 100% protection against severe cases of Covid, according to a new study.
The vaccine is also 79% effective at preventing the virus, new data from the US-led study of more than 30,000 volunteers showed.
The US is expected to approve the sting within weeks as the EU dispute threatens to block cans exported to the UK.
US health officials had been waiting for the final results of their large clinical trial of 32,000 participants there, as well as in Chile and Peru.
The vaccine, manufactured by AstraZeneca, was found to be 79% effective in eliminating Covid-19 symptoms and 100% in preventing serious illnesses.
The results show that it is just as safe and effective in older groups, with no additional risk of blood clots.
The sting has been the subject of controversy in Europe over concerns about links to very rare blood clots but has been declared safe by regulators in the UK and EU.
The results showed that people aged 65 and over had 80% protection against the development of Covid-19.
A total of 141 cases of symptomatic Covid-19 cases were reported in the new studies.
The degree of effectiveness against symptomatic cases was even higher than observed in the clinical studies led by Oxford.
An independent data security monitoring body (DSMB) has also identified no security concerns related to the vaccine.
It conducted a specific review of thrombotic events as well as cerebral venous sinus thrombosis (CVST) – the specific type of cerebral clot that was causing anxiety in Europe.
The DSMB found no increased risk of thrombosis in the 21,583 participants who received at least one vaccine dose. The specific search for CVST found no cases in this study.
A handful of clots among the millions who had come under pressure in Europe had seen some countries that had suspended the rollout to investigate.
This has resulted in a stop-start vaccination program in Europe where uptake is low and infection rates are now rising from the largely unvaccinated populations as a third wave hits the continent.
In addition to the confusion in Europe, France has since reversed its decision on the elderly and stopped vaccinating children under 55 with the Oxford sting while investigating clot problems.
Andrew Pollard, Professor of Pediatric Infections and Immunity and Principal Investigator of the Oxford University Vaccine Study, said, “These results are great news as they show the vaccine’s remarkable effectiveness in a new population and are in line with results from Oxford-led studies.
“We can expect strong effects on Covid-19 in all ages and for people from different backgrounds if we have the vaccine widely used.”
Sarah Gilbert, professor of vaccinology and co-developer of the vaccine, said the new findings “provide further confirmation of the safety and effectiveness” of the sting.
She added, “In many different countries and age groups, the vaccine offers a high level of protection against Covid-19 and we hope this will lead to even more widespread use of the vaccine in efforts around the world to end the pandemic . “
AstraZeneca will now submit data to the US Food and Drug Administration (FDA) and obtain emergency approval for use there.
Professor Gilbert told BBC Radio 4’s Today program: “Twenty percent of the people in this study were over 65 years of age and there was no decline in protection for these people. He was just as good in the 65+ age group as he was younger people in the US, and that is very evident from this process. “
On Europe’s concerns, she added: “I would say the balance remains huge in favor of the use of this vaccine. Thousands of deaths from Covid occur every day across Europe.
“It is really important that we have the opportunity to protect people as soon as possible. This vaccine is available for use in Europe and it will save lives.”
In the US study, two doses were given four weeks apart, while previous studies showed that a longer interval, up to 12 weeks, was more effective.
According to AstraZeneca, leaving an interval longer than four weeks – as is done in the UK – may increase effectiveness and “speed up the number of people who can get their first dose”.
Under an agreement with Oxford, AstraZeneca will supply the vaccine for the duration of the pandemic on a nonprofit basis and in an ongoing agreement for low and middle income countries.
The news comes as polls for YouGov suggests confidence in the safety of the vaccine has fallen in the past two weeks in Spain, Germany, France and Italy following the blood clot panic.
British experts strongly criticized European policymakers who suspended the rollout last week, warning that it would lead to a hesitant vaccine.
The European Medicines Agency (EMA) and the World Health Organization (WHO) have decided that the shock is safe and effective.
The EMA affirmed in a public briefing last week that the vaccine’s benefits outweighed the risks.
However, the YouGov poll seemed to confirm fears that the saga had damaged public confidence in the sting.
55% of Germans said the AstraZeneca vaccine was unsafe, 32% said it was safe.
AstraZeneca’s vaccine has already been classified as unsafe in France, but concerns have only increased. 61% say they are unsure, while 23% say they are safe. This is the result of a survey of almost 9,000 people in seven countries.
Mene Pangalos, Executive Vice President, Research and Development, Biopharmaceuticals at AstraZeneca, said, “These results add to the growing body of evidence showing that this vaccine is well tolerated and highly effective against all levels of Covid-19 and across all age groups is.
“We are confident that this vaccine can play an important role in protecting millions of people worldwide from this deadly virus.”