We are concerned about some of the reaction we have seen from the scientific community in regard to the recent finding that a virus might have contributed to the death of Mr David Bennett, the subject of the controversial experiment in inter-species organ transplantation . A number of responses have attempted to dismiss the failure of this experiment, which resulted in the patient’s death, as an aberration caused by a lack of screening for viruses and contaminants. Some have suggested if that issue is remedied, the procedure can be successful, resulting in a push to ‘try again’. 

We think this shows a substantial error of logic in interpreting the evidence.

We know that the pig was kept in sterile conditions so should have been protected from any infections and was specifically bred to be virus-free. However, the cytomegalovirus (CMV) which is thought to have contributed to Mr Bennett’s death is a herpes-like virus which can lay dormant for a long time before becoming active. The risk of transmission to human patients was identified over four years ago, before we all had more direct experience from Covid-19, of the havoc that mutating zoonotic viruses can wreak. Previous warnings such as Ebola, or SARS-COV-2 were too regional for most people to feel the risk. Clearly “viruses” is a large group, and it is neither possible nor defensible to draw direct analogies from one type of virus to another… But it is clear that scientists are becoming more and more concerned that our interactions with other animals are rapidly increasing the number of viruses that cross species barriers. The current and ongoing global pandemic has thrown this into sharp relief for the general public. The CDC cites that 3 out of every 4 new or emerging infectious diseases in people come from animals, and the World Health Organisation and Wellcome Foundation among others consider zoonoses to be a major and growing public health concern. 

The pig that was used to provide Mr Bennett’s replacement heart was engineered and bred by a United Therapies subsidiary, Revivicor. We are unlikely to ever know how much time and money was spent in developing this one pig, not to mention how many other pigs were bred and kept in isolation for the same purpose, but UT filings show that it spent $304M across the board on research and development in 2022. As there is no license yet for the engineered pig-heart there is no income posted to ascertain its revenue potential. 

We know that many people are waiting for organ transplants and are desperate for hope. Scientists estimate that we are between five and fifteen years away from being able to 3D print human-based organs for transplantation, which is not long in the context of medical research and development, but is cold comfort for patients.  

Given what is known about the potential risks of xenotransplantation both to individuals and also possibly wider populations, not to mention the ethical concerns of the numbers of sentient animals used (pigs are known to have the intelligence of a three-year-old child), we have to ask…  

How much quicker could we get viable human-based organs developed if all the money currently being put into xenotransplantation research was redirected?  

We would hazard a guess that the timescale could be reduced dramatically.  

One zoonotic virus (Covid) has shown what can be achieved when there is political will to direct funding, and scientists in the public and private sectors work together for the common good. Why can’t we take the same approach to solving other health crises instead of pumping money into options that are known to cause suffering and have the potential to cause unintended widespread harm? 

Find out more about the history and ethics of xenotransplants.  

Learn more about the lack of biomedical funding non-animal methods receive in the UK.

You can help create a world where human-relevant research is the norm. 

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