Although fetal-derived cells are used to grow viruses for some COVID-19 vaccines, the cells are not part of the vaccines
Some vaccines require the production of viruses, which can only replicate with the help of living host cells. While certain viruses for vaccines, such as some COVID-19 vaccine candidates, are produced using human fetal-derived cells, these cells and most of their genetic material are removed during the purification process and are therefore not present in the vaccine. Any residual DNA is also broken down into fragments during the purification process, which are harmless and do not affect our DNA.
Inaccurate: Although cells derived from electively aborted fetuses are used to grow viruses for making certain vaccines, the cells and most of their genetic material are removed during the purification process and are therefore not present in the vaccines.
A Facebook video published on 15 November 2020 claims that “aborted fetal tissue” is present in the COVID-19 vaccine produced by AstraZeneca and Oxford University, and that the vaccine can change a person’s DNA. Shared by the anti-vaccine Facebook group “We Are Vaxxed,” the video has received more than 120,000 views and more than 16,000 interactions on the social media platform, according to the social media analytics tool CrowdTangle.
Several vaccines require the production of viruses, which can only replicate with the help of living cells. Human cell strains have been used for decades to produce vaccines, although cells from animals have also been used for the same purpose. For example, the flu vaccine is commonly produced using fertilized chicken eggs, although more newly developed cell-based flu vaccines use an animal cell line, specifically Madin-Darby Canine Kidney cells, for growing the flu virus.
Certain vaccines involve the use of human fetal cell strains, notably the rubella vaccine. According to History of Vaccines, a website by the College of Physicians of Philadelphia:
“In total only two fetuses, both obtained from abortions done by maternal choice, have given rise to the human cell strains used in vaccine development. Neither abortion was performed for the purpose of vaccine development.”
These two cell strains are named WI-38 and MRC5. WI-38 is commonly used to produce the rubella vaccine. History of Vaccines explains the origins of the rubella vaccine:
“In some cases, women who were infected with rubella while pregnant terminated their pregnancies due to the serious risks from congenital rubella syndrome.
Following one such abortion, the fetus was sent to [Stanley] Plotkin at the laboratory he had devoted to rubella research. Testing the kidney of the fetus, Plotkin found and isolated the rubella virus. Separately, Leonard Hayflick (also working at the Wistar Institute at that time) developed a cell strain called WI-38 using lung cells from an aborted fetus. Hayflick found that many viruses, including rubella, grew well in the WI-38, and he showed that it proved to be free of contaminants and safe to use for human vaccines.”
Claims that the cells used to grow viruses for vaccines are present in the vaccines themselves were previously reviewed and found to be inaccurate by Health Feedback here and here. The Vaccine Knowledge Project by Oxford University explains:
“For some vaccines, the active ingredient is grown in laboratories on cultures that contain human cells. Some viruses, such as chickenpox (varicella), grow much better in human cells. After they are grown, the viruses are purified several times to remove the cell culture material. This makes it unlikely that any human material remains in the final vaccine.”
The Vaccine Education Center of the Children’s Hospital of Philadelphia (CHOP):
“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.”
Although fragments of DNA may be present in the final vaccine, the amount is harmless. CHOP explains, “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” and that, “DNA from the vaccine is not able to incorporate itself into cellular DNA.”
The fragmented genetic material also does not differ from the genetic material people come into contact with everyday, for example through our diet. Paul Offit, pediatrician and professor of vaccinology at the University of Pennsylvania, clarified in this 2015 ABC News report:
“There are perhaps nanograms of DNA fragments still found in the vaccine, perhaps billionths of a gram,” he said. “You would find as much if you analyzed the fruits and vegetables you eat.”
While the AstraZeneca/Oxford vaccine uses human fetal-derived cells for growing viruses, it is the HEK293 cell line, not the MRC5 cell strain as claimed in the video. The study which was wrongly cited in the video as supporting evidence for this claim is a preprint, which examined experimental methods for studying the vaccine’s effects, for example efficacy and safety.
Vaccines that use fetal-derived cells in their production have faced objections by some on religious or moral grounds, as the cells used to produce the virus were originally derived from an aborted fetus. Concerns over the use of such vaccines led the Vatican’s Pontifical Academy for Life to issue a statement in 2017 that Catholics could receive vaccines made using human fetal-derived cells, if no alternatives are available:
“The technical characteristics of the production of the vaccines most commonly used in childhood lead us to exclude that there is a morally relevant cooperation between those who use these vaccines today and the practice of voluntary abortion. Hence, we believe that all clinically recommended vaccinations can be used with a clear conscience and that the use of such vaccines does not signify some sort of cooperation with voluntary abortion. While the commitment to ensuring that every vaccine has no connection in its preparation to any material of originating from an abortion, the moral responsibility to vaccinate is reiterated in order to avoid serious health risks for children and the general population.”
Lastly, the video claims, “they know that this vaccine is going to hurt people or kill people so badly.” This claim is baseless and unsupported by scientific evidence. Before a vaccine can be made available to the public, it must undergo safety and efficacy testing in clinical trials (see figure below). Like all medicines, vaccines can produce side effects. However, common side effects from vaccines, such as fever and pain at the injection site, are mild and short-lived.
Figure—The different stages of human clinical trials in vaccine development (modified from the original graphic by the U.S. Centers for Disease Control and Prevention).
Serious adverse events have been reported during the clinical trials of several COVID-19 vaccine candidates, as reported by mainstream media outlets including the BBC, the New York Times, and CNN. It is important to note that these trials were halted once these events were reported in order to determine whether the events were related to the vaccine. The trials were only allowed to continue after safety data was reviewed and no relationship between the vaccine and the adverse event was detected, which is a testament to the emphasis on vaccine safety. As this Nature news report put it:
“‘The clinical hold shows that there are functioning checks and balances, in spite of political pressure,’ says Marie-Paule Kieny, a vaccine researcher at INSERM, the French national health-research institute in Paris. ‘It might indeed remind everybody — even presidents — that for vaccines, safety is paramount,’ she says.“
Correction (19 Nov. 2020):
This review has been corrected to remove an inaccurate reference to WI-38 as the product of a fetus aborted due to congenital rubella syndrome.
Correction (18 Nov. 2020):
This review originally used the term “cell line” to describe fetal-derived cells which are used to produce vaccine viruses. This is inaccurate. The correct term is “cell strain.” The two terms are distinct:
“A cell strain is a cell culture that contains only one type of cell in which the cells are normal and have a finite capacity to replicate. Cell strains can be made by taking subcultures from an original, primary culture until only one type remains. […] However some cells in culture have undergone a mutation, or they have been manipulated in the laboratory, so that they reproduce indefinitely. One example of an immortalized cell line is the so-called HeLa cell line, started from cervical cancer cells taken in the 1950s from a woman named Henrietta Lacks. Cell lines are not used to produce vaccine virus.”