appear to confer is a pretty biased wording. Rather, the only correct way to write about it is "there was a correlation that needs further investigation, we have no idea if there is a causal link about it".

I do not see the bias, all the more so given that the whole article after that first paragraph very clearly explains that further investigation is taking place to determine whether there is such a causal link. I have no idea whether conferring is a strictly defined term in the context of clinical research, but even if it is this is not a scientific journal article but aimed at the general public.

Going in detail to the claim that 'appear to confer' is biased, even if we take such a strict understanding of confer, compare the semantic effect of affirming and negating the sentence with and without 'appear to'

1. 'the vaccines conferred protection'

2. 'the vaccines did not confer protection'

3. 'the vaccines appeared to confer protection'

4. 'the vaccines did not appear to confer protection'

Which of the sentence above is closest to the truth, and which is most inaccurate?

thr vaccine study is a pretty clear (partial) causal link. there is a jump discontinuity in all causes dementia cases based on week of birth, where the jump occurs at the NHS policy cutoff week (if you are older than this week you are ineligible fof the vaccine).

It's likely partial because vaccines only confer resistance against one subset of virii and there may be nonviral Alzheimer's too. in any case causality is not really in question in that study