Then people should be more clear, the argument then only focuses on the ethics of its development, not what is actually in the vaccine.
Do you research the history of medical testing that goes into every pill you take or the safety testing that goes into so many products? You might be surprised if you did. Much evil was used to develop modern medicine and household chemicals and pesticides.
You get no argument from me that it is always unethical to use an aborted baby to test on. The debate is whether knowledge that is gained from that is always immoral to use. Can good be drawn from evil so long as the evil is not approved of? I am not arguing here, either, that this vaccine is good based on other reasons.
Not really:
Some vaccines contain fragments of human DNA/RNA right in the vaccine. Others only in the development. I'm not aware of any that contain DNA in neither.
As regards my own personal due diligence, yes, I avoid any products containing or developed with HEK293. If its in there without my knowledge, this is a non-issue, but as Fr. Scott pointed out (2000), we have a duty to try to inform ourselves; we cannot stay deliberately ignorant.
The easiest solution is to have an organic diet.
PS: Note the similarity in the "this vaccine contains no abortive cells" and the same argument used by the food industry for the last 10 years: "This food was not made with fetal cells." Its a mental reservation, but one which gets Catholics nowhere: Fetal cells WERE used in the development of these snacks and soft drinks, which is a disqualifier:
https://fullfact.org/online/HEK-293-cells/