Then why was it tested for confirmation "efficiacy" on aborted fetal tissue?
WHY?
They didn’t necessarily do the testing but it’s not surprising someone did. This is people just looking for excuses not to vaccinate like it’s a badge of honor. Vaccinate, don’t vaccinate just don’t make things up about what’s in them or who did what in testing, etc. Own the decision made and move on
Why?
Because the FDA requires efficacy testing using HEK 293 cells.
Or is your question “Why does the FDA require this testing procedure?”
They have not deigned to offer an explanation, so no one really knows for sure, though one could speculate.