Re. Staying home from work rules


I have a disabled son who is at high risk of serious complications if he contracts Covid, my wife also. Both received letters to shield.
I am my son’s main carer.

I am so very worried about returning to work, because of this, are there any such rules regarding living with vunerable family members, that will allow me to stay home from work ( without pay) & my job kept open?
I know the vaccine roll out commences soon but my wife & son are 6th on the list to be vaccinated.

Thank you so much