Many patients ask whether Wharton’s jelly stem cell treatments are safe in the era of COVID-19 and vaccines. This article explains, in plain language, what these cells are, how they are prepared, and why, based on current evidence, they are not expected to carry or transmit meaningful amounts of COVID-19 spike protein to patients.
What Is Wharton’s Jelly, and What Are MSCs?
Inside the umbilical cord, there is a soft, gelatin-like tissue called Wharton’s jelly. This tissue surrounds the blood vessels in the cord and helps protect them during pregnancy.
Wharton’s jelly contains mesenchymal stem (or stromal) cells, often shortened to “MSCs.” These cells have been studied for their ability to modulate inflammation and support tissue repair, which is why they are being used in some regenerative medicine applications.
Where Do These Cells Come From?
The MSCs used in Wharton’s jelly products are collected from donated umbilical cords after healthy, full-term births. The cord is normally discarded after delivery, so using it does not affect the mother or baby.
Donors are screened using medical histories and blood tests to reduce the risk of infectious disease transmission and other safety concerns. The tissue is then sent to a specialized laboratory that adheres to quality and safety standards.
How Are the Cells Processed and Cleaned?
In the laboratory, Wharton’s jelly is separated from the cord, broken into small pieces, and the MSCs are isolated and cultured. During this process, the cells are washed and expanded over multiple passages, which separates the final product from the original raw tissue.
This matters for safety because free proteins, cell debris, and other contaminants from the original tissue are diluted and washed away over time. Final products are also tested for contamination, including bacteria and fungi, and may be tested for selected viruses in accordance with laboratory protocols and regulations.
What About COVID-19 and the Spike Protein?
COVID-19 is caused by the virus SARS-CoV-2, which uses its spike protein to enter human cells. Some patients worry that donor cells might carry the spike protein and somehow transfer COVID-related material to them.
Based on current evidence, Wharton’s jelly MSC products are not expected to be a meaningful source of spike protein for several reasons.
First, these MSCs appear to be poor hosts for SARS-CoV-2 because they generally show low expression of the main entry factors the virus uses, such as ACE2 and TMPRSS2. ACE2 and TMPRSS2 are proteins on the surface of some cells that act like the “locks and tools” the virus needs to open the door and enter the cell. These stem cells have very few of these proteins, so the virus has a difficult time infecting them. In placental studies, viral material and spike protein have been found mainly in trophoblasts and Hofbauer cells rather than in mesenchymal stromal cell populations used for therapy.
Second, spike protein in the human body is generally short-lived. After infection or vaccination, the spike protein and the genetic instructions that produce it are normally broken down over days to weeks rather than being stored in stem cells long term. Although some newer studies report that tiny amounts of spike protein or spike fragments may persist for much longer in certain people with long COVID or post-vaccination syndromes, those findings come from highly selected groups and involve specific tissue niches such as the skull-meninges-brain axis, immune cells, or vascular tissues, not Wharton’s jelly MSC products.
Third, donor selection reduces theoretical risk. Donor programs typically use healthy, full-term births and exclude mothers with active infection or other high-risk conditions at the time of donation.
Finally, the manufacturing process adds another layer of protection. The cells are separated from the original tissue, cultured, and washed multiple times, so any free spike protein or other transient material present in the starting tissue would be expected to be diluted, degraded, and removed during processing.
Taken together, current evidence does not support the idea that Wharton’s jelly MSC products act as carriers of COVID-19 or significant reservoirs of spike protein.
What About MUSE Cells From Cord Blood?
A special type of stem cell called a MUSE cell (short for “Multilineage-differentiating Stress-Enduring” cell) is found as a rare subpopulation within mesenchymal cells, including those in cord blood.
These MUSE cells share the same low levels of the viral entry molecules ACE2 and TMPRSS2 as regular cord-derived mesenchymal stem cells, which means they are also poor “hosts” for the COVID-19 virus.
When MUSE cells are isolated from cord blood and prepared for treatment, whether given via IV or injected into a joint, they undergo the same donor screening, laboratory purification, and repeated washing steps.
For these reasons, the same safety logic applies. Cord-blood MUSE cell products are also not expected to carry meaningful amounts of COVID-19 spike protein.
Taken together, current evidence does not support the idea that Wharton’s jelly MSC products or cord-blood MUSE cell products act as carriers of COVID-19 or significant reservoirs of spike protein.
What Safety Checks Are in Place?
Reputable clinics and laboratories follow several safety measures, including donor medical screening, blood testing for infectious diseases, processing in controlled laboratory settings, and release testing before products are used in patients.
Results can vary from person to person, and these therapies should be viewed as part of an evolving field of regenerative medicine rather than as a guaranteed cure.
What Are the Risks and Unknowns?
Like any medical treatment, Wharton’s jelly MSC therapy has risks and unknowns. These may include temporary soreness or swelling at the injection site, a low but possible risk of infection or reaction, and uncertainty about the best long-term protocols and outcomes.
For most conditions, these products are not yet formally FDA-approved, and their use is based on emerging clinical experience and ongoing scientific study rather than fully settled evidence.
From the information available so far, the concern that these cells are loaded with COVID-19 spike protein and can pass it on to patients remains theoretical and is not supported by current evidence.
Questions to Ask Your Provider
If you are considering Wharton’s jelly MSC treatment, useful questions include:
- Where do the cells come from, and how are donors screened?
- Which laboratory processes the tissue, and what quality standards does it follow?
- What condition is being treated, and what outcomes have been seen in similar patients?
- What are the realistic benefits, limitations, and alternatives in this specific case?
Clear discussion with a physician can help patients weigh the potential benefits, uncertainties, and safety considerations in a balanced way.
– Dr. Purita
