Last week, the Trump administration instituted a policy shift that bans or heavily restricts the use of human fetal tissue for medical research. The new policy extends restrictions placed on federal employees of the National Institutes of Health (NIH) that were imposed last fall to many of those who merely receive NIH grant funding for their research. All those affected will now be required to sit before an ethics panel and justify the use of fetal tissue in their research. Neither the members of this ethics panel nor the definition of the ethics that will be investigated have been described. Depending on how those details come together, we may once again face a moratorium on fetal tissue research in the United States, as we did during the Reagan and George H.W. Bush administrations before it was lifted in 1993.
Many of the researchers who may be most affected by this policy change study pathways and processes associated with disease in infants and children. As such, the only certain consequence of the new policy is that it will impede medical discoveries that could advance new treatments to save the lives of infants, the very lives those in favor of this policy claim they are trying to protect.
I am a virologist with an interest in discovering the pathways that viruses use to infect cells, with a specific emphasis on viruses that threaten fetal and neonatal health. A little over 10 years ago, my research interests took an unexpected turn when I learned I was pregnant with my son. At first, I was elated, but then very quickly I became terrified — could the viruses I work with on an almost daily basis hurt my unborn child? I scoured the scientific literature for answers. From these searches, I learned that the placenta forms the sole barrier to the spread of viruses from the mother to the fetus. I also discovered that we knew little about how the placenta fulfills this important role. Within weeks, I shifted my research focus to discover how the placenta protects the fetus from viral infections.
The placenta is arguably the most essential organ for the development of human life. It both forms a barrier to protect the fetus from infections and provides nutrients to the fetus while also managing waste exchange from the fetus to the mother’s blood. To meet these needs, the placenta changes and adapts as pregnancy progresses from just a few cells to a fully formed fetus ready for delivery in the third trimester. These changes affect many aspects of placental development, some of which remain incompletely understood. Nonetheless, it is clear that the placenta that develops in the first and second trimesters of pregnancy is quite different from that which is collected post-delivery. Since most of the viruses that cause severe birth defects and fetal death do so in the first and second trimesters, it is critical to perform studies in healthy placentas isolated from early in pregnancy, which are usually collected following an abortion. Given that the placenta is a fetal tissue that develops from a fertilized egg, our research could now be banned or limited by the Trump administration.
Our research has improved our understanding of how the placenta protects the fetus against viral infections. With it, we’re building a road map of the routes that viruses can use to cross the placenta to reach the fetus. Through this work, we have identified placental cell types that so potently restrict viral infections that they essentially form a roadblock, informing us that these cells are unlikely to be viral portals. However, some viruses do cross the placenta and damage the fetus. Our research therefore also aims to identify how these viruses do this, to develop strategies to stop them. For example, we have worked with others to identify the pathways that Zika virus might use to bypass the placenta and the impact of the mother’s immune response to the virus on placental structure and function. Even as we have made progress, we are still working to solve other puzzles. Is there an expressway that some viruses use to cross the placenta? Are there detours that some viruses find that allow them to bypass the roadblocks? The new government restrictions could make answering these questions almost impossible.
To say that the new government restrictions could be devastating to scientific research in the United States is an understatement. As a consequence of this policy, our ability to understand and fight many types of human disease may be significantly slowed or completely halted. For example, an ongoing study at the University of California at San Francisco using fetal tissue to generate mice with humanlike properties to improve HIV therapeutics was halted last week. I anticipate that our research and the research of others studying the placenta will be similarly halted or delayed in the coming months. Quite often, those opposed to the use of fetal tissue argue that no discoveries that have improved human health have resulted from research using this tissue. Even a cursory search of the scientific literature shows that this statement is simply not true. The use of fetal tissue has led to fundamental discoveries including improving treatments for HIV, defining the cellular components associated with Alzheimer’s disease, identifying the placental cell types targeted by pathogens associated with fetal disease, the development of treatments aimed at improving dementia or other neurodegenerative disorders and the development of vaccines that have saved the lives of millions.
As all of this suggests, the debate on whether fetal tissue should be used for medical research appears to be based far more in politics than in a desire to improve human or infant health. But the vast majority of us have witnessed a child’s remarkable recovery from an infection or disease that would have killed the child just a few decades ago. We have scientific and medical research — some of which, such as the poliovirus vaccine, used fetal tissue — to thank for these improvements. It is therefore troubling to consider that the politicians involved in this recent policy change may be putting political gains over the health and welfare of citizens.