Lord Sumption:

The position in the United Kingdom is that there is a statutory power under the public health Act to require someone to undergo testing if there is reasonable grounds for believing that he or she is infected. There is no statutory power to compel to be tested people who are not believed to be currently infected. As to vaccination, there is no power to require people to be vaccinated. The public health Act expressly provides that the powers are not available to compel people to undergo any form of treatment, and vaccination would unquestionably be regarded as a form of treatment.