The coronavirus vaccine developed by teams at the University of Oxford has been shown to trigger a robust immune response in healthy adults aged 56-69 and those over 70 years of age.
The findings published in 'Lancet' on Thursday based on 560 healthy adult volunteers shows that the ChAdOx1 nCoV-19 vaccine is "safe and well tolerated" with a lower reactogenicity profile in older adults than in younger adults, meaning the older age groups could build immunity to the disease.
"These findings are encouraging because older individuals are at disproportionate risk of severe COVID-19 and so any vaccine adopted for use against SARS-CoV-2 [COVID-19] must be effective in older adults," the researchers note.
The team is also testing whether the vaccine stops people developing COVID-19 in larger Phase 3 trials and early results from this crucial stage are expected in the coming weeks.
"We were pleased to see that our vaccine was not only well tolerated in older adults, but also stimulated similar immune responses to those seen in younger volunteers," said Dr Maheshi Ramasamy, an investigator at the Oxford Vaccine Group.
"The next step will be to see if this translates into protection from the disease itself," she said.
This means there are now four promising vaccines on the horizon after Pfizer-BioNTech, Sputnik and Moderna already reporting good preliminary data from Phase 3 trials.
The UK has already ordered 100 million doses of the Oxford vaccine, being manufactured by pharma major AstraZeneca.
The vaccine also has a tie-up with the Serum Institute of India.
