[kypro]

I shared the link because I hadn't heard about the infertility risk before and I found a lot of conflicting information when I looked it up – with many main stream sources dismissing the claim out of hand.

My understanding is that, yes, the proteins are similar, but not the same, and that a similar protein also exists in influenza which does not cause infertility when targeted by our antibodies. I assume this doesn't mean that it couldn't cause infertility in the case of a COVID-19 vaccine, but it would suggest it's perhaps unlikely.

Is there any reason to believe an mRNA vaccine would be anymore likely to cause our antibodies to target the syncytin-1 spike protein as opposed to a more traditional vaccine?

I do agree with your point that it's more a question of the probability of side effects than a possibility. This is something that's bothered me about the attacks on those who are hesitant on the safety of these vaccines. Although I'm sure there's a very low risk that someone will suffer any adverse effects from these vaccines there is almost certainly going to be some cases of adverse side effects, so in the interest of public trust in the COVID-19 vaccines and all future vaccines we should be ensuring the public understand the risks fully and not attacking anyone for asking questions or expressing doubts, because if it does turn out that some of those doubts did indeed hold merit then no one will trust a word the media or professors have to say on this in the future.