The UK population has been asked to practice social distancing during national lockdowns. But one newly created category of people have been asked to pay special care to reduce their own exposure to COVID-19. These ‘clinically extremely vulnerable’ people were asked to take action beyond normal social distancing to protect themselves. In this presentation we describe the creation and reception of the Shielded Persons List (SPL) created by NHS Digital. We aim to show the visible and less visible effects of this novel category. By drawing on data from survey and ethnographic studies we reflect on impacts of the list’s creation, application, communication and revision on different groups of people. The uptake of the guidance has varied depending on how much individuals felt they were being appropriately categorised, and also whether they feel that the guidance matched their own risk perceptions. We argue that uncertainty about whether this category ‘fits’ an individual relates to applications of automated algorithm, which may feel impersonal or perhaps ill-suited when applied to an individual. Unpacking these processes helps to clarify why responses to this list have been so varied, and how this might help us understand future applications of automated algorithms in healthcare.