Environmental factors? You're absolutely right. It's not only Pfizer though. My only child was abou to be born ten years ago, my wife very aware if very pregnant women take flu shot during pregnancy, something might happen to the fetus inside the womb. How many times nurses kept bugging my wife if she wanted flu shot, HPV shot, whatever shot while already at labor and delivery bed almost about to give birth. I was just holding my temper, almost freaked out, "what the f*ck you people bugging my wife to get flu shot, don't you f*cking people know it might heart the fetus inside?"
My boy now almost teen. Oftentimes we see badly developmentally disable child in the playground, I'd ask the mom if she had flu shot while her child still in the womb, often, "that Kaiser nurse kept bugging me for flu shot while I was very pregnant and I gave in."