There has been a lot of misinformation published about the Trump Administration’s decision to halt funding for experiments involving fetal tissue research. Below are rebuttals to the most common fallacies we’ve seen.
Claim 1: “Research using fetal tissue has led to lifesaving advances, including development of vaccines.”
Fresh aborted fetal tissue has never been used in vaccine production. The original Salk and Sabin polio vaccines used monkey tissue to grow virus. While there are a couple of historical cell lines that were grown from abortions in the 1960s, kept in cell culture, and used for some vaccines, even these cell lines are antiquated and no longer used for most vaccines today. For example, much of the polio vaccine today is made using the Vero monkey cell line.
Many modern vaccines use animal cell lines, even insect cell lines, as well as modern human cells that are not from fetal tissue. As just a couple of examples, the new Ebola vaccine – recently shown to be 97.5% effective – is produced using the Vero monkey cell line, and the recently approved shingles vaccine (Shingrix) which is a modern recombinant subunit vaccine produced in engineered hamster cells, also than 90% effectiveness while providing better protection than the historical vaccine produced in fetal cells.
Rubella: Hilleman actually developed the first rubella vaccine using animal cells. Plotkin developed his rubella vaccine in 1969 using the WI-38 human cell line. Ethical versions of vaccines for rubella (Japan only) and rabies are currently available using alternatives (hen, quail, rabbit). We never needed any form of fetal cells from historic abortions to develop these vaccines.
Rabies: The rabies vaccine went thru various stages starting with Pasteur, who grew the virus in rabbit brains that were then desiccated. Later versions used sheep or goat brain or chicken embryos, or hamster kidney cells. The rabies vaccine approved in the 1970’s used virus grown in the MRC-5 human cell line, not fresh fetal tissue.
Bottom line: Cell cultures and cell lines have been grown in the lab for years or even decades, they’re not fetal tissue. Another example would be HeLa cells, from a human cervical carcinoma, also used in the past for growth of poliovirus. They are in no way a tissue or organ, and to characterize them in that way displays either ignorance of the science or willful deception.
Claim 2: “We need research using fetal tissue to find new treatment for HIV.”
Some claim that fetal tissue is “needed” because BLT humanized mice generated with fetal bone marrow/liver/thymus tissue have been used to study HIV infection, human immune response, and antiretroviral treatments, and to test new therapies (i.e., Truvada). However, the BLT mouse is only one model among many other animal and non-fetal models that have been used to study HIV. There are several other model systems available to researchers for studying HIV, including nonhuman primates, which are considered the most relevant animal model for HIV/AIDS research to date.
Fetal tissue is not needed to develop drugs for HIV. Humanized mouse models used to research HIV and test therapeutics can be made (and many have been) using alternatives including peripheral blood, cord blood, bone marrow, and neonatal thymus tissue. A recent study showed that the alternative mouse model made with hematopoietic stem cells is sufficient, meaning we don’t need fetal tissue, for the study of HIV infection, pathogenesis, and therapy. Plus, humanized mice made with peripheral blood are an ideal model for rapid drug discovery and were used in early testing of therapeutics including Enbrel for rheumatoid arthritis.
Several advantages to using alternatives—the mice are easier to prepare at lower cost, more animals can be generated per cohort, there is negligible graft-versus-host disease and longer life span, chronic HIV infection is longer-lasting, and long-term safety and toxicity assessments are possible. Humanized mice generated with fetal tissue are more technically difficult, costly, time consuming, and not as efficient as the other models.
Claim 3: “…fetal tissue is still making an impact, with clinical trials underway using cells from fetal tissue to treat conditions including Parkinson’s disease, ALS, and spinal cord injury.”
Doug Melton, co-director of Harvard’s Stem Cell Institute and president of the International Society for Stem Cell Research, is quoted saying this.
Melton refers to fetal stem cells, not fresh fetal tissue. The things mentioned are being tested in some limited clinical trials, but are not yet showing any published success. Those trials are not being funded by taxpayer money, but instead are funded by private companies.
Claim 4: “the scientific consensus is there is no adequate substitute for fetal tissues in some research areas.”
Sally Temple of the Neural Stem Cell Institute has said, “the scientific consensus is there is no adequate substitute for fetal tissues in some research areas. For example, to learn how the mosquito-borne Zika virus moves from a pregnant woman’s bloodstream into her fetus and attacks the developing brain — and how to prevent that — requires studying fetal brain cells.”
Because the Zika virus infects the brains of babies in utero, some researchers want to obtain brains of aborted babies (usually 9-13 weeks’ gestation) in order to study viral infection. Some researchers perform direct observational studies on the brains while others will isolate stem cells from the tissue to study the mechanism of infection.
We know from published studies that organoids, three-dimensional organ-like structures constructed using modern stem cell techniques, are incredible models for studying Zika infection. These organoids have been instrumental in deciphering both normal brain development and the mechanism of Zika virus action on the developing brain. In one example, a seminal study in the journal Science showed that brain organoids can recapitulate the mechanism of how Zika infects human cells and causes the same microcephaly observed in humans.
There is no consensus; various scientists have published multiple papers showing not only numerous alternatives, but alternatives that are more efficient and better scientifically. E.g., Brown et al. on the NeoThy humanized mouse.
This article is adapted from written testimony Dr. Prentice and Dr. Sander Lee provided to Congress, as well as, a Charlotte Lozier Institute fact sheet on aborted fetal tissue.