The efficacy of the vaccine was determined after a large-scale trial involving 20,000 volunteers.
The researchers said the vaccine can be up to 90% effective when subjects are given a low dose followed by a high one.
A total of 2,741 people were on the course that proved 90% effective, while 8,895 were given two full doses.
Andrew Pollard, director of the Oxford vaccine group and chief investigator of the Oxford vaccine trial, 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.”
Oxford’s breakthrough comes less than a month after Pfizer and BioNTech announced that they had developed a vaccine that is 90 percent effective in preventing COVID-19.
Unlike the Pfizer vaccine which needs to be stored at 70 degrees celsius, the Oxford vaccine can be stored at 2-8 °C, making distribution and storage easier.