Many times we forget this because, fortunately, we do not witness daily the death and hardship caused by the infectious diseases that ravaged the world until the development of vaccines.
Interestingly, this strength constitutes one of its weaknesses today. In the absence of an imminent real danger, many do not see the urgency of vaccinating their children. This endangers your life and that of the rest of the people who have not been able to get vaccinated.
The desired vaccine against SARS-CoV-2 has not been spared from picturesque pronouncements against it. Antonio Cañizares, archbishop of Valencia, assures that the vaccine “is made from cells of aborted fetuses”, which he describes as “inhuman and cruel.”
Anyone who hears these statements will imagine a factory through which human fetuses enter a kind of blender and from which a distilled liquid comes out that protects us against the virus. This is clearly not the case. So where does that claim come from?
In the middle of the last century we saw vaccines against diseases that plagued humanity such as polio, measles, rubella and rabies. It was the great time of the development of these drugs.
These vaccines were produced by infecting cells in laboratory culture to allow viruses to multiply. They were later inactivated to produce inactivated vaccines, or grown under conditions that facilitated loss of virulence to generate attenuated virus vaccines.
In order to carry out these virus preparations, safe and well-defined cell cultures were required, which for the time was a challenge. It was common to use cells derived from monkeys , which entailed the risk of carrying virus from these animals as a contaminant. This is what happened with the SV-40 papovirus in some polio vaccine preparations.
There was also the fear of using human cells derived from tumors, since the basis of the origin of the cancer was not clear. The possibility of the disease being transmitted as an infectious agent posed a huge risk.
In this context, the Wistar Institute in Philadelphia (USA), one of the most active in the development of vaccines, decided to hire a young local scientist, Leonard “Len” Hayflick, to be in charge of the cell cultures that were to serve the scientists to generate their vaccines.
Hayflick reasoned that the safest and most defined system for generating vaccines should consist of a culture of primary cells (obtained directly from the body), not exposed to infection or tumor processes. Using tissue from healthy aborted fetuses seemed like the best option.
During his first attempts he succeeded in establishing various lines of fetal fibroblasts that he numbered WI-1 through WI-25 (by Wistar Institute and the successive attempt number).
Hayflick received fetal tissue from medical abortions at a nearby hospital in his laboratory. He carried it next to a Bunsen burner and, armed with scalpels and trypsin solution, he chopped and disintegrated it until obtaining a suspension of individualized cells.
These cells adhered to the culture plates, adapted to grow with the nutritive media that were added, and divided robustly and profusely. Every so often their number doubled. Hayflick persistently noted how many cells he planted on the plates, the number he obtained, and the time it took for the cells to fill the plate.
In this way, he observed that primary cells from healthy human tissue have a limited “fertile” period during which they are capable of dividing. However, after about fifty the cells ceased their proliferation. Despite remaining metabolically active, they were unable to divide again.
This observation, contrary to the dogma of the time that established that cells were immortal, marked the beginning of the area of research in cellular aging.
The cells that Hayflick had obtained were infectible by many viruses and could be frozen and thawed without losing viability. This allowed them to be used to grow viruses and produce vaccines. For this reason, he decided to generate a new cell line that he would expand until obtaining a large number of cells that he could use for that purpose.
In June 1962, Sven Gard, director of the Virology department at the Karolinska Institute in Sweden, contacted Hayflick to offer him tissue from a legally aborted fetus in a Swedish hospital.
The lungs of that fetus, wrapped in moistened gauze, traveled to Philadelphia by plane, where they were received by Hayflick. Working in the way he already knew, he began cultivating fibroblasts. He multiplied the cells for weeks until, after 9 doublings, he reached hundreds of containers full of cells. With the help of several technicians and after a marathon session, the cells were collected, distributed in hundreds of vials and frozen.
This is how the WI-38 line was created.
These cells were used at the Wistar Institute itself by Hilary Koprowsky, a pioneer in the development of the polio vaccine, and Stanley Plotkin, fundamental in the rubella vaccine.
Additionally, Hayflick was actively involved in promoting its WI-38s. For this, he sent vials to all interested laboratories to seek support and recognition, as well as to promote the development of new vaccines.
Hundreds of researchers and several drug companies put WI-38 to good use. This made it possible to discover a multitude of biological processes, but also to develop vaccines against rubella, measles, rabies and polio.
Without a doubt, we can affirm that WI-38 has saved hundreds of millions of human lives over more than half a century.
WI-38 are not the only primary human cells derived from human fetuses that have been used. The MRC-5, obtained in 1966 by British scientists, made it possible to generate vaccines for chickenpox, polio and the famous MMR (against measles, rubella and mumps).
In any case, the Vatican has already ruled in favor of the use of vaccines produced in these cells through a letter from the then Bishop Elio Sgreccia, president of the Pontifical Academy for Life.
I trust that, after this brief historical walk, readers will understand that Archbishop Cañizares’ statement distorts reality. Furthermore, affirming that “first [the fetus] is killed and then manipulated [to generate the vaccine]” is a misrepresentation of the truth that we could qualify as diabolical.
Manuel Collado Rodríguez, Researcher Miguel Servet II, director of the research laboratory on Stem Cells in Cancer and Aging
This article was originally published on The Conversation. Read the original.
