Vaccine policies and challenge trials: the ethics of relative risk in public health

In this St Cross Special Ethics Seminar, Dr Sarah Chan explores three key areas of risk in ‘challenge trials’ – the deliberate infection of human participants to infectious agents as a tool for vaccine development and improving our knowledge of disease biology. Dr Chan explores a) whether some forms of challenge trials cannot be ethically justified; b) why stratifying populations for vaccine allocation by risk profile can result in unjust risk distribution; and c) how comparing these cases and the evaluation of relative risk reveals flaws in approach to pandemic public health.