Thank you for this thread and raising awareness - I am in the CEV group but I have to time my vaccination very carefully based on my immune-suppressant drug schedule. This weekend was optimal, if i didn't get it done this weekend I was waiting another four weeks to the end of the next cycle. All week checking the post - no letter, no letter, and then I tried the website with my details yesterday morning after I saw this post and it let me book for today!
I did bring my shielding letter and most recent consultant write-up, just in case, but other than not being able to find a booking reference from my GP, I explained I did it direct and that was fine.
Thank you so, so much, and I hope it encourages others to get it done rather than wait around if they don't have to!