In attempts to balance the benefits and harms potentially involved in xenotransplantation, the benefits for the prospective patients have been subordinated to the potential risks of
unleashing a xenogeneic pandemic. National and international restrictions on clinical research and trials have been set in place in order to exclude the risks for the public, but they may not prove to be fully effective for both practical and ethical reasons. The question we have attempted to answer here is whether the requirement of those stringent public health measures is inevitable. We argued that, even though the harm principle dictates that harm-doing is unacceptable when it is also other-regarding, the impermissibility of harming public health is not a moral absolute. In particular, an assessment of the acceptability is dependent on whether the promised benefits are attainable and perceived as such by the public. Furthermore, there is a particular responsibility to take account of those risk factors that have a predictable, foreseeable effect. It can be argued that accountability for a pandemic that results from an unforeseen effect of xenotransplantation should not necessarily be attributed to those involved in the development and use of the technology alone. The permissibility of harm-doing is then rendered an issue of medical ethics, in which a weighing of harms against the benefits of the procedure for the patient is of paramount importance.