US Health and Human Services secretary says the vaccines could possibly be used for inoculation as soon as this year.
British drugs group AstraZeneca and the University of Oxford say their jointly-developed vaccine against COVID-19 has shown “an average efficacy of 70 percent” in trials.
“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,” AstraZeneca chief executive Pascal Soriot said in a statement on Monday.
The results ranged between 62 and 90-percent efficacy, depending on the vaccine dosage.
The 70-percent average is lower compared with the efficacy of coronavirus vaccines trialled by rivals Pfizer/BioNTech and Moderna which have come in above 90 percent.
AstraZeneca said it will immediately apply for early approval of the vaccine where possible, and it will seek an emergency use listing from the World Health Organization, so it can make the shot available in low-income countries.
Monday’s statement said: “Positive high-level results from an interim analysis of clinical trials of AZD1222 in the UK and Brazil showed the vaccine was highly effective in preventing COVID-19… and no hospitalisations or severe cases of the disease were reported in participants.”
It added: “One dosing regimen (n=2,741) showed vaccine efficacy of 90 percent when AZD1222 was given as a half dose, followed by a full dose at least one month apart.”
The pair said that regimen n=8,895 showed 62-percent efficacy when given as two full doses at least one month apart.
“The combined analysis from both dosing regimens (n=11,636) resulted in an average efficacy of 70 percent.”
AstraZeneca said it would “immediately prepare regulatory submission of the data to authorities around the world that have a framework in place for conditional or early approval”.
It added that it would seek emergency-use listing from the World Health Organization to accelerate vaccine availability in low-income countries.
Al Jazeera’s Jonah Hull, reporting from London, said: “It has been shown that this vaccine is far more practical than the other vaccines that are going for a regulatory approval in the United States, in a sense that it is able to be stored at 2 to 8 degrees, as opposed to, for instance, minus 70 degrees in the case of the Pfizer vaccine.
“And it is also going to be able to be produced much more widely, scaled up much more quicker and much cheaper than the other vaccines. These have hugely important implications for the developing world, for the distribution of the vaccine globally.”
AstraZeneca, which has pledged it won’t make a profit on the vaccine during the pandemic, has reached agreements with governments and international health organisations that put its cost at about $2.50 a dose. Pfizer’s vaccine costs about $20 a dose, while Moderna’s is $15 to $25, based on agreements the companies have struck to supply their vaccines to the US government.
AstraZeneca said it is looking at a capacity of up to three billion doses of the vaccine in 2021 pending regulatory approval.
It said the vaccine can be stored, transported and handled “at normal refrigerated conditions” of between two and eight degrees Celsius (36-46 degrees Fahrenheit) for at least six months.
“The announcement today takes us another step closer to the time when we can use vaccines to bring an end to the devastation caused by SARS-CoV-2. We will continue to work to provide the detailed information to regulators. It has been a privilege to be part of this multi-national effort which will reap benefits for the whole world,” said Sarah Gilbert, professor of vaccinology at the University of Oxford.
More than 23,000 adults are currently being assessed in the trials, with the number expected to rise to up to 60,000, the statement said.
“Clinical trials are also being conducted in the US, Japan, Russia, South Africa, Kenya and Latin America with planned trials in other European and Asian countries,” it added.
Oxford professor Andrew Pollard said the latest findings show “an effective vaccine that will save many lives”.
“Excitingly, we’ve found that one of our dosing regimens may be around 90 percent 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,” added Pollard, who is chief investigator of the Oxford Vaccine Trial.
UK Prime Minister Boris Johnson said on Twitter: “Incredibly exciting news the Oxford vaccine has proved so effective in trials… There are still further safety checks ahead, but these are fantastic results.”
Matt Hancock, health secretary, told BBC TV: “We hope to be able to start vaccinating next month.
“The bulk of the vaccine rollout programme will be in January, February, March. And we hope that sometime after Easter things will be able to start to get back to normal.”