My theory was that Apoptoxin was created as a immortality/youth pill by the black org, and that the whole orginization is centered around it and its successful creation.
The project failed though, and it started killing people and leaving no trace, and that's what they started using it as.
Flash foward to the amusement park day with Shinichi, where he was hit with a side-effect that the wiki says was a one-in-a-million chance (though I'm not sure whether this information is canon)
Now this is what always bothered me about Haibara's character - she broke this suspension of disbelief for me. People dropping dead where ever Conan went? Sure! The same officers every shift? Why not?
But if this info is in-universe, it's really not likely that she too would get the side effect, because that would then amp up the chances to one in TWO million, and wow, that's high, almost too high.
I'm not being a good detective here because it's not impossible, it's just improbable. Since detective conan is an anime series, i might be looking too much into this but still, maybe this is our link!
Those chances are just too low to not eliminate and it's more likely that to survive Apoptoxin you have to have conditions and that it's not a matter of chance.
1. It is specially engineered for the boss (like maybe Vermouth) and Shinichi and Haibara are relatives of her. (which would wreck havoc on some shipping charts now that I think of it)
2. The key to surviving it is a High IQ
3. Something unique about their blood or bodies that the victims share. Here I'll assume that Vermouth is the third victim.
Which also makes me propose this: If number three were true, remember that Shinichi also has Ran's blood inside of him.
After seeing the Clash of Red and Black, it made me wonder if Gosho would make this plot-relevant. That would be interesting.