The study of 560 healthy adults, including 240 over the age of 70-years-old, found the vaccine to be safe and produced a similar immune response among people aged over 56-years-old and those aged between 18 and 55.
British pharmaceutical giant AstraZeneca, which is working in collaboration with the University of Oxford, has previously said interim data showed their experimental vaccine had produced an immune response in older and younger adults.
The authors of the Oxford study said their results could be encouraging if the immune responses are found to be associated with protection against Covid-19 infection.
The phase two trial did not assess vaccine efficacy, however, and phase three trials are ongoing to confirm this
https://www.cnbc.com/2020/11/19/oxford-covid-vaccine-prompts-immune-response-among-all-adults-study.html 
Oxford Covid vaccine trials indicate it is safe, produces similar immune response among all adults
British pharmaceutical giant AstraZeneca, which is working in collaboration with the University of Oxford, has previously said interim data showed their experimental vaccine had produced an immune response in older and younger adults.
The authors of the Oxford study said their results could be encouraging if the immune responses are found to be associated with protection against Covid-19 infection.
The phase two trial did not assess vaccine efficacy, however, and phase three trials are ongoing to confirm this
https://www.cnbc.com/2020/11/19/oxford-covid-vaccine-prompts-immune-response-among-all-adults-study.html