I too get called for a flu jab and this appears to make me vulnerable but not severely vulnerable. I am also over 70 so that is also a vulnerability.
No letters from the governmenet, although Sainsbury do seem to give me "slots".
I have had pneumonia. I am asthmatic and, just to add a little gloss, I had major heart surgery 2nd May 2020. So I am mega mega vulnerable. But no letters, no words of advice, no help with food parcels etc
So I have stayed home for the 12 weeks that I was asked to stay home, well I will be when the 12 weeks ends on Sunday 7th June.
I would point out that I dont think we were asked to isolate. I think we were asked to stay at home. But there was so much conflicting words that others will probably disagree.
What seems certain is that we, whatever you call us, have now been totally abandonned. I would love to find I am wrong and that Boris gets on the TV and sets out what he recommends for us lot.
But I am pretty sure there will be nothing. If all of us start to go to the supermarket on 3rd June then the supermarkets will be overwhelmed.
In your individual case, the question is...are you fit to work at your job ? I dont think a government letter will help on this score. If you are to be asked to ignore "social distancing" then you should not be back at work.
The effects on me of a stroke rendered me incapable of working for three years and more. OK, I had retired, but no way can I work.
good luck Wendy
Colin