BBC news reports (https://www.bbc.co.uk/news/health-52542109) reveal a number of worries the advisers had about some of the strategies (such as immunity passports).
Documents are available here: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/882726/29-pre-empting-possible-negative-behavioural-responses-covid-19-antibody-testing-13042020.pdf
Democratically Accountable Modelling 