The Facts About Fetal Cells and Covid Vaccines Explained

Fact-checking claims about fetal cells being present in vaccines

If you follow the anti-vaxx crowd then you will have heard the claims being bandied about on social media. Vaccines contain fetal cells from aborted fetuses. Where do these claims come from, do they have any basis in fact, or are they simply scare tactics latched onto by the anti-vaxx community to scare you off using vaccines? We’ll examine the exact mechanisms of how vaccines are developed and produced to explain this misinterpreted construct.

First of all, it’s important to draw a strong distinction between the older lines of cultured fetal lung cells and other organ cells, referred to below (the cells we’re discussing in this article), and freshly harvested tissue required for the extraction of stem cells for murine experimentation. Fetal cell lines are cells that grow in a laboratory. They descend from cells taken from elective abortions in the 1970s and 1980s. Those individual cells have since multiplied into many new cells over the past four or five decades, creating fetal cell lines.

Current fetal cell lines are thousands of generations removed from the original fetal tissue. They do not contain any tissue from a fetus. Vaccine development relies on these fetal cell lines. Although not relevant to this discussion, readers may gain insight from this article about the importance of fetal cell cultures and stem cells to research and scientific advances.

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The cells we’re discussing shouldn’t be confused with fetal stem cells either, which were first isolated and cultured by John Gearhart and his team at the Johns Hopkins University School of Medicine in 1998 (Shamblott et al., 1998). These cells known as primordial germ cells are the precursors of eggs and sperms and were isolated from the gonadal ridges and mesenteries of 5–9-week fetuses obtained by therapeutic abortion. Embryonic germ (EG) cells isolated from them are found to be pluripotent. Challenges associated with the isolation of these stem cells are (1) they can be obtained only from 8- to 9-week-old fetuses and (2) EG cells have limited proliferation capacity, so they cannot be kept viable for an extended period.

None of the COVID-19 vaccines in development use fetal cells taken from recent abortions.


The preferred type of fetal cell to culture vaccines in is called a fibroblast. Fibroblast cells hold skin and other connective tissue together. The fetal fibroblast cells used to grow vaccine viruses were first obtained from elective termination of two pregnancies in the early 1960s. These same fetal cells have continued to grow in the laboratory and are used to make vaccines today. No further sources of fetal cells are needed to make these vaccines.

Fetal cells are particularly suited to the task of growing vaccines.

  • Viruses need cells to grow and tend to grow better in cells from humans than animals (because they infect humans).
  • Almost all cells die after they have divided a certain number of times; scientifically, this number is known as the Hayflick limit. For most cell lines, including fetal cells, it is around 50 divisions; however, because fetal cells have not divided as many times as other cell types, they can be used longer. Our ability to maintain cells at very low temperatures in liquid nitrogen has enabled scientists to continue using the same fetal cell lines- almost 60 years later – that were first isolated in the 1960s.

As scientists studied these viruses in the lab, they found that the best cells to use were the fetal cells mentioned above. When it was time to make a vaccine, they continued growing the viruses in the cells that worked best during these earlier studies.

Comparing Apples with Apples

According to Nature, cell lines derived from aborted fetal tissue have been fairly commonplace in research and medicine since the creation in the 1960s of the WI-38 cell strain, which was derived at the Wistar Institute in Philadelphia, Pennsylvania, and MRC-5, which came from a Medical Research Council laboratory in London. Viruses multiply readily in these cells, and they are used to manufacture many globally important vaccines, including those against measles, rubella, rabies, chickenpox, shingles, and hepatitis A.

An estimated 5.8 billion people have received vaccines produced on these two cell lines which, with others, have become standard laboratory tools in studies of aging and drug toxicity. (Research with such lines is not covered by US regulations governing the use of fresh fetal cells and tissue nor captured in the NIH database.) In the past 25 years, fetal cell lines have been used in a roster of medical advances, including the production of a blockbuster arthritis drug and therapeutic proteins that fight cystic fibrosis and hemophilia.

Just so we know what we’re actually discussing here let’s group the covid vaccines currently in circulation and see how each one is affected by the fetal cell debate. Here’s a really useful infographic from the WHO to help identify each.

Courtesy of WHO

Vaccine makers may use fetal cell lines in any of the following three stages of vaccine development:

  • Development: Identifying what works
  • Confirmation: Making sure it works
  • Production: Manufacturing the formula that works

mRNA Vaccines

Neither the Pfizer nor Moderna vaccines used fetal cell lines during the development or production phases. (So, no fetal cell lines were used to manufacture the vaccine, and they are not inside the injection you receive from your doctor.) Both companies, have however used the fetal cell line HEK 293 in the confirmation phase to ensure the vaccines work. All HEK 293 cells are descended from tissue taken from a 1973 elective abortion that took place in the Netherlands.

So no chance of any contamination for the mRNA vaccines or any potential for the inclusion of DNA material.

Adenovirus Vaccines

The Johnson & Johnson vaccine is an adenovirus vector vaccine. (Adenovirus is the virus that causes the common cold. The virus in this vaccine has been changed so that it does NOT cause illness.) With this type of vaccine, a carrier, in this case, adenovirus, acts as a delivery vehicle. The adenovirus has had the coronavirus spike protein added to its DNA.

The adenovirus carries that genetic material into your body, delivering its modified DNA to your cells. Your cells will then make the spike protein, activating your immune system. Once activated, your immune system creates antibodies to fight off the spike protein. Materials for the production of these types of vaccines are grown in fetal cell cultures.

Johnson and Johnson’s adenovirus vaccine

Vaccines for varicella (chickenpox), rubella (the “R” in the MMR vaccine), hepatitis A, rabies (one version), and COVID-19 (one U.S.-approved version) are all made by growing the viruses in the original fetal cell lines described above. All of these, except for the covid vaccine, are made using fibroblast cells. The covid vaccine from Johnson & Johnson (J&J)/Janssen is made using fetal retinal cells (PER.C6).

The retinal cells used to make the covid adenovirus vaccine (J&J/Janssen) were isolated from a fetus terminated in 1985. The cells were subsequently adapted for use in growing adenovirus-based vaccines in the late 1990s.

Adenovirus-based vaccines that cannot replicate when administered to people need to be produced in cells that have the necessary gene to allow for large quantities of the virus to be made. The retinal cell line, called PER.C6, was adapted to enable the production of these altered viruses. Even though fetal cells are used to grow vaccine viruses, vaccines do not contain these cells or pieces of DNA that are recognizable as human DNA. People can be reassured by the following:

  • When viruses grow in cells, the cells are killed because in most cases the new viruses burst the cells to be released.
  • Once the vaccine virus is grown, it is purified, so that cellular debris and growth reagents are removed.
  • During this process of purification, any remaining cellular DNA is also broken down.

AstraZeneca Vaccine

During its development, the Oxford-AstraZeneca vaccine used kidney cell lines from a fetus aborted in 1973. The modified cells are used to help the vaccine replicate (a ‘vaccine factory’) and are then removed before the vaccine is completed. The method of production is not dissimilar from the Johnson and Johnson vaccine and at the risk of repeating myself, simply refer to the section above.

What about DNA Contamination?

This is only applicable to covid vaccines grown in fetal cell cultures (adenovirus) and we’ve discussed the mRNA transfer of materials to your DNA extensively in this vaccine-related article here. Adenoviruses are members of the viral family that are responsible for the common cold. This is important as none of the viral material in our DNA originates from this family of viruses.

The only viruses known to be able to integrate with our DNA are retroviruses. The coronaviruses and adenoviruses are not retroviruses, the HIV virus is an example of a retrovirus. Around 8% of our genetic material is comprised of our brushes with retroviruses over a period spanning hundreds of thousands of years. In addition to this important factor, the following precludes DNA transfer from an adenovirus vaccine to a human

  • Integrase — A person’s DNA cannot be changed without the presence of an enzyme, called integrase. Integrase is not an ingredient in either adenovirus covid vaccine.
  • Stability of DNA — Because DNA is not stable when exposed to certain chemicals, much of it is destroyed in the process of making the vaccine. Therefore, the amount of human DNA in the final vaccine preparation is minimal (trillionths of a gram) and highly fragmented. Because the DNA is fragmented, it cannot possibly create a whole protein that could be harmful.
  • Opportunity — DNA from the vaccine is not able to incorporate itself into cellular DNA. In fact, if this could be accomplished, gene therapy would be much easier than it has been.

Medika encourages anyone with concerns about the use of fetal cell lines in vaccine development to weigh the risks and benefits of the Covid vaccines with their doctor and have a personal conversation with a faith leader.

The Vatican has issued clear guidance that permits Roman Catholics in good faith to receive COVID-19 vaccines that use fetal cell lines in development or production.


  1. Children’s Hospital of Philidelphia. Vaccine Ingredients — Fetal Cells
  2. Nebraska Medicine. Do the COVID-19 vaccines contain aborted fetal cells
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Medika Life has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your health care provider(s). We encourage you to discuss any decisions about treatment or care with your health care provider. The mention of any product, service, or therapy is not an endorsement by Medika Life

This article lives here: Consumer SafetyThe Facts About Fetal Cells and Covid Vaccines Explained
Robert Turner
Robert is a Founder of Medika Life. He is a published author and owner of Cre8tive Digital Media. He lives between the Philippines and the UK. and is an outspoken advocate for human rights. Access to basic healthcare and eradicating racial and gender bias in medicine are key motivators behind the Medika website and reflect Robert's passion for accessible medical care globally.

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