I think you need to read up on the hayflick limit.AnthonyMartin wrote: ↑Wed Sep 02, 2026 9:58 am Thanks for the resources. I certainly didn’t intend to be misleading. How far removed would it need to be acceptable? I would understand that the cell lines are thousands of cell generations removed from the original fetus?
Roughly speaking, with some mild variation each cell is capable of replicating 52 times.
1 - 2 - 4 - 8 - 16 - 32 - 64 - 128 - 256 - 512 and so on.
Now, I’m sure you can see that wouldn’t actually amount to enough for vaccine production.
What they did was they took about a gram of cells and replicated them to the 16th generation I believe. Then they split it into multiple vials.
This information is specific for the WI-38 and I can look it up and find the sourcing documents if you need it.
So I’m not positive how they did it with the other cell lines, but probably something similar.
The international health organization was very concerned about the supplier of MRC 5 and WI-38 and had published a document containing the information about what remained available. China has documented the reasoning behind creating two cell lines to replace these two, The US has also replaced them, although not started using the new cell lines.
Bottom line they are not thousands of generations removed. The maximum replication is actually very similar to how we have a finite lifespan as well.
For vaccine production, you want under 40 generations.
So let’s say, hypothetically, that the cell would last forever and we’d never need a new line. I still would object, but my stance would be pretty weak to convince anyone else. As it is, replacement cell lines have been made and medicine almost across-the-board is adopting fetal cell testing or manufacturing in some fashion.