Oxford Covid vaccine given boost after promising immune response in over-60s

The results are ‘encouraging’, researchers say

The Oxford coronavirus vaccine shows a promising immune response in participants over 60, data from phase 2 trials has suggested, boosting hopes that it will be able to help protect people in the most vulnerable age brackets.

Researchers described the phase 2 findings as “encouraging”, and results from the crucial late stage trial are expected within weeks. 

The development follows promising results in phase 3 trials from three other candidates, with Pfizer-BioNTech, Sputnik and Moderna all raising hopes of a successful vaccine on the horizon.

Significantly, the candidate developed by Pfizer and BioNTech appears to be effective in 94 per cent of over-65s, data from its ongoing phase 3 trial has shown. This is particularly reassuring because older people, who are most at risk from the virus and have weaker immune systems, tend not to respond as effectively to vaccines as younger adults.

The UK has ordered 100 million doses of the Oxford vaccine, 40 million doses of the Pfizer-BioNTech vaccine and five million of the Moderna vaccine. The Oxford vaccine is manufactured by AstraZeneca.

Researchers said participants in the Oxford trial developed similar immune responses across the three age groups: 18-55, 56-69, and 70 and over.

Dr Maheshi Ramasamy, an investigator at the Oxford Vaccine Group, said: "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.

"The next step will be to see if this translates into protection from the disease itself."

Two weeks following the second dose of the Oxford vaccine, more than 99 per cent of people of all ages had neutralising antibody responses.

Dr Ramasamy added: "The robust antibody and T-cell responses seen in older people in our study are encouraging. The populations at greatest risk of serious Covid-19 disease include people with existing health conditions and older adults.

"We hope that this means our vaccine will help to protect some of the most vulnerable people in society, but further research will be needed before we can be sure."

Volunteers in older age groups were also less likely to experience side-effects from Oxford’s ChAdOx1 nCov-2019 vaccine, which were usually mild.

No serious safety issues have been recorded related to the vaccine.