It is a matter of choice. Any of the three vaccines currently available in the UK will likely cause relapse in ME/CFS, because the mechanism of action of any vaccine always involves stimulation of the immune system, which is why vaccines are generally not advised in this illness. There is therefore a recognisable risk to being vaccinated.
On the other hand, a bout of Covid infection will also cause relapse, possibly more serious than the equivalent relapse from a vaccine. The alternative approach would be to avoid vaccination altogether and continue self- isolating. Anyone visiting or caring for you should also be vaccinated beforehand, constituting a cordon sanitaire.
I am also hoping that, by the middle of this year the campaign of vaccination will have created enough herd immunity such that transmission eventually ceases. Thus two options: I am marginally in favour of the second one, provided the self isolation is effective and all visitors/fellow residents have been vaccinated. Please note that this advice is given on the assumption that you have no other chronic medical conditions, necessitating a different approach.
A final point: Vitamin D is highly protective against Covid19 infection in that it prevents the more serious manifestations of the disease. Anyone suitably topped up with Vitamin D is much more likely to suffer a mild, self limiting illness. The dose I recommend for adults is 2000 units colecalciferol daily. As above, this advice assumes that you have no other chronic medical conditions for which Vitamin D intake may have to be adjusted accordingly. In such cases, I suggest you speak to your GP.
Dr William R C Weir FRCP, FRCP (Edin)