I am part of the Novavax trial so may have already had the injection (or a saline placebo). There are about 15,000 people in the UK currently undergoing this trial. I had a period of 2 hours of chills as a side effect after the vaccine. Thats all. Been absolutely fine since. I have the second vaccine next week.
Novavax is very similar to the Oxford vaccine but a few months behind so data won't be out for a good few weeks yet. It is not an mRNA vaccine.
We have been told as well if we are offered a different vaccine they will unbind the trial for us so we know what we have already had.
These vaccines have not been rushed. Hundreds of Billions of pounds have been poured into these vaccines, they have been running stages concurrently when there would normally be a year or twos gap between as they secure funding for the next stage. All these problems have been eliminated by the sheer amount of money being poured in.
It is up to an individual, but I do think businesses, airlines etc... could refuse you access if you do not have a vaccination.