It’s no secret: thousands of medical laboratories around the world use cells from a fetus that was aborted decades ago to develop drugs and vaccines. But through research on immunization and therapy against Covid-19, this fact is attracting new attention, because the cells are also in use here. At the beginning of October, anti-abortion opponents protested against its use in the USA, claiming it was ethically unacceptable.
The doctor Andrea Gambotto rejects this criticism. “It would be a crime not to use the cells,” says Gambotto, who researches vaccinations at the University of Pittsburgh. He has been using the cells with the designation HEK 293 for 25 years. “They have never harmed anyone. Cells from a dead embryo are used for research instead of being thrown away, ”argues the scientist.
The advantage of the cells, which were made “immortal” in the early 1970s, is that they are standard in the pharmaceutical industry, explains Gambotto. Should he one day succeed in developing a vaccine against Covid-19 in his laboratory, every factory will be able to manufacture it on a large scale thanks to HEK 293. The doctor considers it superfluous to develop an alternative to the cell line: “Why should we reinvent the wheel?”
The Canadian researcher Frank Graham succeeded in 1973 at the University of Leiden in the Netherlands in transforming the cells. Usually the number of divisions in a cell is finite. Graham modified the cells so that they keep dividing. It worked on the 293rd attempt – hence the name of the cell. HEK stands for “human embryonic kidney cells”.
“It wasn’t uncommon to use fetal tissue back then,” says Frank Graham, now Professor Emeritus at McMaster University in Canada. “Abortion was illegal in the Netherlands until 1984, except to save the mother’s life. That is why I have always assumed that the cells used in the Leiden laboratory came from a therapeutic abortion ”.
Vaccine developers like to use HEK 293 because the cells are malleable and can be turned into small virus factories. To grow viruses, you need a host cell. This may be a hen’s egg, but human cells are preferred in human medicine.
The viruses are needed for a type of vaccine that gives a weakened and modified virus. In the case of Covid-19, several laboratories are using HEK 293 cells to produce mutated and harmless viruses that have the typical tips of the coronavirus on their surface. When this virus is injected into people, the immune system produces antibodies that protect against infection with the real coronavirus.
Three of the very advanced vaccine projects use HEK 293: that of the pharmaceutical company AstraZeneca in collaboration with Oxford University, that of the Chinese company CanSino and that of the Russian Gamaleya Institute. Other companies, such as Pfizer and Regeneron, use it to make “fake coronaviruses” that they use to test their vaccines or drugs.
Vaccines against Ebola and tuberculosis have also already been developed on the basis of HEK 293. “I am very pleased that the cells I created nearly 50 years ago have played an important role in many advances in biomedical research,” says Graham. He does not want to comment on the criticism of the origin of the cells.