AstraZeneca Oxford vaccine is 70% effective on average, data shows

The vaccine developed by the University of Oxford and AstraZeneca stops 70 percent of people developing COVID-19 symptoms. A second regimen showed 62% efficacy when given as two full doses at least one month apart.

The Pfizer/BioNTech vaccine was 94 percent effective among people over the age of 65, which experts described as very important as the virus spreads across the globe at a record rate. "Excitingly, we've found that one of our dosing regimens may be around 90 per cent effective".

The news comes as AstraZeneca and Oxford said Monday their vaccine was as much as 90% effective in preventing COVID-19, marking the latest candidate to inch closer toward approval.

Oxford professor Andrew Pollard said the latest findings show "an effective vaccine that will save many lives". Further data is expected next month, but Pollard said there was no reason to think that it would substantially change the current figures.

There were no hospitalized or severe cases of Covid-19 reported in the studies.

The Oxford-AstraZeneca vaccine does not use mRNA technology and instead involves an inactivated common cold virus isolated from chimpanzees, altered with genes to express the spike protein of the SARS-CoV-2 virus. "Maybe it's good for some people and not as good for other people", Cohen said.

"It may seem confusing that a higher initial dose gives a less favourable response, but this may just be due to a residual response in some patients to the disabled "vehicle", a snippet of chimpanzee virus used to deliver the vaccine "payload", said Stephen Griffin, Associate Professor in the School of Medicine, University of Leeds.

That averages to a 70% efficacy, AstraZeneca said.

On Friday, AstraZeneca told CNN that the company had already delivered four million vials of its vaccine candidate to the United Kingdom government, and that millions more frozen doses were ready to be sent.

"Once final data are available across all three trials, it would be helpful to undertake a combined analysis to fully understand any differences in efficacy across difference population groups", said Ghani.

The company said it was making "rapid progress" in manufacturing, with a capacity of up to 3 billion doses of the vaccine in 2021 on a rolling basis, pending regulatory approval.

Researchers, meanwhile, are now submitting data to the European Medicines Agency and the U.K.'s Medicines and Healthcare products Regulatory Agency on a rolling basis.

It added that it would seek emergency-use listing from the World Health Organization to accelerate vaccine availability in low-income countries.

Another notable advantage of the vaccine is that it can be stored under normal fridge conditions, rather than in freezers, and therefore distributed via existing channels.