Oh wow I see, thanks for the pointer! Looking it up now, it seems the increased risk was 1 in 18400, or 0.005%. [1] So I guess it was rare enough that it could

Oh wow I see, thanks for the pointer! Looking it up now, it seems the increased risk was 1 in 18400, or 0.005%. [1] So I guess it was rare enough that it could easily not have shown up during trials either. One key point in my question that I'm stuck on, though, if you happen to know the answer: how long did the effects take to become apparent in those children? Were they immediate or did they show up long after vaccination? (I'm mainly wondering how long people should expect to wait before side effects become apparent.) [1] https://en.wikipedia.org/wiki/Pandemrix https://en.wikipedia.org/wiki/Pandemrix