I should clarify, I was responding to a question from another poster who asked whether people with underlying health conditions would be placed in the 4th priority group for the COVID vaccination, and my answer was NO, only people who are required to shield due to being extremely clinically...
Tier 4 does not include those with underlying health issues. It includes those who are clinically extremely vulnerable, who were advised to shield in the first national lockdown, and have been advised to shield again.