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What is the context behind the misinformation about fetal cells used in the AstraZeneca COVID-19 vaccine?

This article was published on
April 21, 2021

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The Oxford-AstraZeneca COVID-19 vaccine (AZD1222) does not contain human cells or tissues. The AZD122 (ChAdOx1 nCov-19) is a weakened version of an adenovirus—a harmless virus that usually causes the common cold in chimpanzees— and is used as a way to transport the vaccine's ingredients into the human body. This type of vaccine is called a "vector vaccine," because the adenovirus serves as the vector (or vehicle) for getting the drug into human cells. The adenovirus can stimulate a response from a person's immune system when their body detects it in cells. Essentially, the vaccine helps train human bodies to detect and eliminate a real COVID-19 infection through showing it mock spike proteins, before COVID-19 can cause any severe symptoms or a severe infection. During preclinical research, MRC-5 cells were used to determine how effective the vaccine may be in human clinical trials, but the MRC-5 cells are not used in the manufacturing process for this vaccine. There are different processes used to make vaccines. Often, when vaccines are being made, viruses are propagated (grown in the lab) in special laboratory cells, and the viruses are then collected to make the vaccine. To make this COVID-19 vaccine, the virus is propagated using another type of cells, the HEK 293 cell line. However, there is no evidence that these cells are present in the vaccine itself. The cells are removed through a filtering and purification process that breaks down the cellular pieces and remaining DNA before a vaccine is deployed to humans. The HEK 293 cells and MRC-5 cells (mentioned above), as well as many other research cell lines, were collected from fetal tissue in the 1960s and 1970s. Since then, labs have reproduced those cell lines for some medical purposes, including research and vaccine development. These cells are not part of the vaccine. It is also important to distinguish between fetal cells and cultured (lab grown) cells. Fetal cells are not used in vaccine production.

The Oxford-AstraZeneca COVID-19 vaccine (AZD1222) does not contain human cells or tissues. The AZD122 (ChAdOx1 nCov-19) is a weakened version of an adenovirus—a harmless virus that usually causes the common cold in chimpanzees— and is used as a way to transport the vaccine's ingredients into the human body. This type of vaccine is called a "vector vaccine," because the adenovirus serves as the vector (or vehicle) for getting the drug into human cells. The adenovirus can stimulate a response from a person's immune system when their body detects it in cells. Essentially, the vaccine helps train human bodies to detect and eliminate a real COVID-19 infection through showing it mock spike proteins, before COVID-19 can cause any severe symptoms or a severe infection. During preclinical research, MRC-5 cells were used to determine how effective the vaccine may be in human clinical trials, but the MRC-5 cells are not used in the manufacturing process for this vaccine. There are different processes used to make vaccines. Often, when vaccines are being made, viruses are propagated (grown in the lab) in special laboratory cells, and the viruses are then collected to make the vaccine. To make this COVID-19 vaccine, the virus is propagated using another type of cells, the HEK 293 cell line. However, there is no evidence that these cells are present in the vaccine itself. The cells are removed through a filtering and purification process that breaks down the cellular pieces and remaining DNA before a vaccine is deployed to humans. The HEK 293 cells and MRC-5 cells (mentioned above), as well as many other research cell lines, were collected from fetal tissue in the 1960s and 1970s. Since then, labs have reproduced those cell lines for some medical purposes, including research and vaccine development. These cells are not part of the vaccine. It is also important to distinguish between fetal cells and cultured (lab grown) cells. Fetal cells are not used in vaccine production.

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What our experts say

The Oxford-AstraZeneca COVID-19 vaccine (AZD1222) does not contain human cells or tissues. The AZD122 (ChAdOx1 nCov-19) is a weakened version of an adenovirus—a harmless virus that usually causes the common cold in chimpanzees— and is used as a way to transport the vaccine's ingredients into the human body. This type of vaccine is called a "vector vaccine," because the adenovirus serves as the vector (or vehicle) for getting the drug into human cells. The adenovirus can stimulate a response from a person's immune system when their body detects it in cells. Essentially, the vaccine helps train human bodies to detect and eliminate a real COVID-19 infection through showing it mock spike proteins, before COVID-19 can cause any severe symptoms or a severe infection.

During preclinical research, MRC-5 cells were used to determine how effective the vaccine may be in human clinical trials, but the MRC-5 cells are not used in the manufacturing process for this vaccine.

There are different processes used to make vaccines. Often, when vaccines are being made, viruses are propagated (grown in the lab) in special laboratory cells, and the viruses are then collected to make the vaccine. To make this COVID-19 vaccine, the virus is propagated using another type of cells, the HEK 293 cell line. However, there is no evidence that these cells are present in the vaccine itself. The cells are removed through a filtering and purification process that breaks down the cellular pieces and remaining DNA before a vaccine is deployed to humans.

The HEK 293 cells and MRC-5 cells (mentioned above), as well as many other research cell lines, were collected from fetal tissue in the 1960s and 1970s. Since then, labs have reproduced those cell lines for some medical purposes, including research and vaccine development. These cells are not part of the vaccine. It is also important to distinguish between fetal cells and cultured (lab grown) cells. Fetal cells are not used in vaccine production.

Context and background

In a video about the AstraZeneca COVID-19 vaccine that was shared across social media platforms, a host encouraged viewers to share false information, telling them to avoid the COVID-19 vaccine if they do not want “aborted fetal tissue fragments put into them or their DNA fragments changed.” The host also says falsely that there is aborted fetal lung tissue in the vaccine. 

Many different types of cells are used in medical research and vaccine production and development, and MRC-5 cells, originally obtained in 1966 from the lungs of a 14-week aborted male fetus, are used commonly. HEK 293 cells, originally obtained from embryonic kidney tissue, are also commonly used.   Additionally, while there can be residual DNA in vaccines, it is not recognizable as human DNA.  Research has suggested that there could be some DNA present when a vaccine is made using cells, but the DNA exposure is unlikely to be harmful, because the DNA is very fragmented (broken into small parts). 

The US Food and Drug Administration limits the size and amount of DNA in vaccines and while we are not aware of any risks associated with DNA fragments that could be present in vaccines, the exact level of risk is not defined.    Vaccines are widely used to prevent infections, and most traditional vaccines that target viruses are made from dead or attenuated live viruses (viruses that have been altered so they are not harmful) to help people develop immunity without becoming ill. The viruses used to make these vaccines do not grow (or multiply) in liquids or on agar plates (like bacteria or fungi) so, during vaccine production and development, a virus is cultured (or grown) in special cells in a laboratory. Sometimes these cells, called “cultured cells,” are grown under controlled laboratory conditions and, in some instances, are replicated from human fetal cells.

Resources

  1. MRC-5 (ATCC CCL-171) (ATCC)
  2. 293 [HEK-293](ATTC CRL-1573) (ATTC)
  3. SARS-CoV-2 candidate vaccine ChAdOx1 nCoV-19 infection of human cell lines reveals a normal low range of viral backbone gene expression alongside very high levels of SARS-CoV-2 S glycoprotein expression (Research Square)
  4. ChAdOx1 nCoV-19 vaccination prevents SARS-CoV-2 pneumonia in rhesus macaques (bioRxiv)
  5. A single dose of ChAdOx1 MERS provides protective immunity in rhesus macaques (Sci Adv)
  6. Vaccine Ingredients- DNA (Children’s Hospital of Philadelphia)
  7. Vaccines and Related Biological Products Advisory Committee 154th Meeting (FDA)
  8. Bioethics News: Is it true that there are vaccines produced using aborted fetus cells? (Bioethics Research Laboratory, Georgetown University)
  9. Vaccine Ingredient- Fetal Tissues (Children’s Hospital of Philadelphia)

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