Ravelingien et al¹ argue that, given the restrictions that must be imposed on recipients of xenotransplanted organs, we should conduct clinical trials of xenotransplantation only on patients in a persistent vegetative state. I argue that there is no ethical barrier to using terminally ill patients instead. Such patients can choose to waive their rights to the liberties that xenotransplantation would probably restrict; it is surely rational to prefer to waive your rights rather than to die, and permissible to allow patients to make this choice.

Perhaps the single most important advance in the history of moral thought occurred when it came to be generally recognised that all people are protected by rights that are inviolable, at least without their consent. The precise nature and content of these rights is controversial, but there is a consensus among reasonable people over their core. We all have a right to life, to liberty, to security of person and to equality before the law. Other rights—so-called positive rights, such as the right to economic security, or cultural rights, for instance—may be controversial, but we all agree at least on these.

Ravelingien et al¹ therefore seem to be on solid ground when they conclude that it would not be permissible to use living persons as subjects in clinical trials of xenotransplantation, as such trials, potentially or actually, result in the violation of the core human rights of the subjects. Their argument is as follows:


 Xenotransplantation carries with it a currently unquantifiable risk of the transmission of viruses, from the animal that is the source of the organ transplanted, to the human recipient. Such viruses could have potentially catastrophic consequences, up to and including triggering a global and devastating pandemic. Therefore, it would be necessary to monitor the health status of recipients of …