Is it worth carrying on as a guinea pig, if a vaccine has already been found? Francis Beckett

I am 75 and taking part in the Novavax trial but the success of the Oxford jab has given me a dilemma

My third appointment with researchers this week, as a participant in Covid-19 vaccine trials, was overshadowed by the news that the Oxford vaccine will probably be available to older folk like me in the early part of next year - maybe as early as January or February.

The vaccine I am trialling - the Novavax one - will have test results in January, and probably be available in the summer. So what happens to us guinea pigs when the Oxford vaccine is available, I wanted to know. As a reasonably healthy 75-year-old, I'm likely to be - in the doctor's words - at the back of the front of the queue" for it. I have signed up to be in the Novavax study for a year. But if I have the Oxford vaccine, do I cease to be any use?