Taking the vaccine is in no way participating in murder. The foetal cells which were used to produce the cells in the vaccine were gotten by way of murder, yes, but for your receipt of those cells to be participating in murder, it'd have to mean that you receiving anything that was originally gotten by murder is somehow participating in it. If some guy murders his brother for the inheritance, then a few generations later the murderer's great-grandson buys a watch with some of the money passed down to him, does the watchmaker participate in the man's murder by coming into possession of money that came from money that came from a murder that happened before he was even born? Obviously not.
There's a strong argument to be made that you participate in the desecration of the fetus' corpse by participating in the continuation of that line, or that you encourage future abortions by making abortive vaccines profitable. And that's not even getting into the fact that you're likely aiding tyrants in their efforts at population control, at the detriment of your own health. But the participation in murder argument is just nonsensical.