A. There maybe adverse reactions. They are likely to be a few people having anaphylactic shock, it happens with many vaccines, but the number is very low. Some may feel a bit ill for a few days as that seems to happen with some vaccines too. There is a risk of other problems, those seem to be neurological such as being prone to fainting or chronic fatigue for long periods after vaccination, those are not large numbers but possible.
Best to keep an eye out for reports of adverse reactions in reputable sources and have a vaccination a month or so after it has been released in the UK providing the risks seem ok.

The best place to keep an eye out for them are the Cochrane database, which does metta-analysis of drug trials, it has a corona section, and the RxISC website, where people put up their own reports of drug adverse reactions.

For an account of how to assess vaccine risks this book gives you details of how it can be done, it debunks anti-vax scares but is critical of some vaccines on an evidence based statistical models.
https://www.amazon.co.uk/dp/B0848FPKNP

Link to the Cochrane database Covid 19 section https://www.cochrane.org/news/cochrane-clinical-answers-related-covid-19

This is the RxISC website, put vaccine in it and could find no side effects listed which indicates that they do not give large numbers of adverse reactions which is in link with what the Doctors tell us https://rxisk.org/

This is important too though: “Prof Allyson Pollock (director of the Newcastle University Centre for Excellence in Regulatory Science) has tweeted, “In the Interests of transparency all clinical study reports should be published and in the public domain now.” Pfizer UK Country Manager Ben Osborn told Reuters, “We have provided complete data packages, the unblinded data, to both regulators. I think what you’re seeing is just the difference in the underlying process and timelines, as opposed to any difference in data submission.” So why hasn’t the UK government published this? It’s vital people have confidence in the vaccine and the approval process. Transparency would help with this – people couldn’t claim the wool was being pulled over the public’s eyes.”
https://www.reuters.com/article/health-coronavirus-britain-eu/update-1-eu-warns-of-risks-of-covid-19-vaccine-race-after-uk-approval-of-pfizer-shot-idUSL1N2II0N3

Regulatory capture is a real thing

Outline from John Hoggett