Animal-To-Human Transplant Progress: What Are the Risks and Concerns?

Organ transplantation saves lives, but, unfortunately, it cannot happen often enough to help everyone on the waiting lists. Some forward-thinking researchers and tech company workers believe animal-to-human transplant operations are the way forward. Although they would not wholly solve the problem, they could provide alternatives for those who cannot feasibly wait for human donors to become available. However, some people have some concerns about moving forward with this approach.

Animal-To-Human Transplant Options

Animal-to-human transplants — also known as xenotransplantation — involve using nonhuman organs, tissues or cells to treat medical conditions in humans. Pigs have emerged as the top animal choices for organ candidates because of their anatomical similarities to humans and the fact that they are easy to breed and have large litters. 

However, as early as the 1960s, scientists began exploring the feasibility of transplanting chimpanzee organs into humans. Although the people did not survive for the long term, the things learned in those efforts have shaped more recent attempts. Even so, animal-to-human transplant procedures are still few and far between. As work progresses to make them viable, some people have raised valid objections. 

Animal Rights and Welfare

Several of the issues surrounding this matter relate to animal welfare. For example, at Revivcor, a biotech company based in Virginia, female pigs get embryos surgically implanted and eventually bear cloned piglets. Although these animals live on a farm where people reportedly take great care to keep them healthy, some concerned individuals point out that it is unethical to breed and kill animals that are solely created for human benefit. 

More broadly, this approach centers on anthropocentrism or the view that humans should have moral preference over all other beings. Numerous related issues arise from this stance. Breeding animals for their organs necessitates a new kind of farming and corporate-driven business model. Additionally, because the science of xenotransplantation is still relatively new and yet to enjoy widespread success, the ethics question is more complex than asking if people find it acceptable to trade one animal’s life to save a human. 

The more realistic scenario is that numerous animals must die, and a human might live longer as a result. Scientific research requires ongoing trial-and-error attempts. Most of these biotech companies are building business models based on the anticipation of future success rather than the virtual guarantee of it. 

Some concerned parties assert that the better option is to invest time and money into methods that allow patients to receive transplants and survive but do not require animals to die for that outcome. A Portuguese company called Orgavalue proposes an option that uses human cadavers for organ transplantation. Many people are already familiar with and supportive of becoming organ donors if they get into fatal accidents, so this possibility could appear more palatable to them. 

Animal Viruses Transmitted to Humans

Scientists already know of many viruses that can spread to humans through animal exposure. Could those issues worsen if animal-to-transplant efforts become more widespread? That is not entirely out of the question, and indeed, this issue has already become apparent recently.

The first transplant of a pig heart into a human happened in 2022, but that attempt ended prematurely. Although the operation went smoothly and the heart initially performed well, the patient’s condition worsened about 40 days after the procedure, and he died a couple of months later. Although those involved did not immediately know or speculate about the cause of death, it later emerged that the heart contained porcine cytomegalovirus. It is too much of a leap to say that the preventable infection caused the man’s death. However, evidence does link it to transplant failures. People can never know whether the patient would have lived longer if the heart was virus-free, either. There are simply too many potentially contributing factors at play. 

The main thing to remember here is that the ramifications of these viruses could have far-reaching effects. Besides reducing the chances of successful transplants, this kind of transmission could spread into the wider population and introduce new human health risks. 

As of 2023, more than 100,000 people were on organ waiting lists in the U.S. alone. Additionally, thousands of people die annually because they do not receive the transplants in time. It’s clear that a genuine problem exists, but human-to-animal transplant procedures are not the only options for solving it. 

For example, researchers are working on 3D-printed organs made from synthetic materials and used for transplantation. If those eventually become viable, they could eliminate the risks of animals transmitting viruses to humans through their infected organs. 

Diversions of Critical Resources 

It’s easy to see the potential of animal-to-human transplants, especially when the recipients have few or no options left. Many would understandably consent to experimental procedures once doctors say they will almost certainly die without them and may live at least a bit longer by having these transplants done. 

Although transplants from animals to humans capture headlines and public attention, they have so far failed to cause any significant life extensions or improvements for those receiving them. A stark example came in 2023 when a pig’s kidney worked for a record-setting two months inside the brain-dead recipient. 

Those involved said that milestone marked a critical point in paving the way for eventually using those animal organs in living humans. However, such goals are incredibly costly and require numerous skilled health care professionals on the transplant teams. 

Is it not a better, more realistic use of resources to continue focusing on medications and therapies that help people live longer despite organ failure diagnoses? Although risk-taking is often necessary to achieve medical progress, those involved must ask themselves whether the extraordinary resource usage is worth the likely impacts for the patients who receive the animal transplants. 

If there were a well-established history of thousands of patients receiving these transplants and continuing to survive for several years afterward, it would be easier to justify proceeding with such efforts. Indeed, researchers cannot hope that these transplants will become more successful without continuing to attempt them.

However, some physicians assert that it makes more sense to prioritize methods that prevent organ failure or make transplants from human donors more viable. Additionally, ramping up targeted campaigns to encourage organ donation could make headway. Collectively, these options could prove more successful than xenotransplantation.

Animal-To-Human Transplant Operations Raise Questions

Although it is understandable why many people see the potential of using animals to shorten human transplant waiting lists, it is equally easy to see why some feel hesitant about proceeding with this option. It is far from a clear-cut issue, and that reality has elevated some of the matters covered here.