In my comment and the post (which thank you for reading by the way) I was mostly talking in terms of effectiveness rather than safety but you seem to want to talk about safety so I’ll bite.

The scientific process is not a straight line, especially for a statement such as “does [blank] cause [blank]”. To test these type of statements studies are designed and data is collected. Data can be “noisy” in that if an effect is small and hard to measure it can sometimes be hard to spot. The noise may sometimes point one way or another, either confirming the statement or refuting the statement. Overtime however a picture becomes clear. What you have sent me is a small selection of the studies that confirming the statement, this however does not reflect the extensive research literature on which a decision is ultimately made.

In my tiny sliver of expertise (the psychology of vaccination) I am currently dealing with around 1000 published papers (similar in style to those that you’ve sent me here). My job across my PhD is to make sense of the existing literature and add to it, it has taken me 4 years of full time work to just about make sense of it all and I’m only now starting to become confident that I am an expert in my field.

Safety is not my area of study, but the process is the same for the scientists that cover it (it’s also a much larger area of vaccine science than mine with thousands of papers being published each year). They take all the literature, including the studies that you’ve linked to, assess them for quality and effect size (which is why me posting 25 links to papers would ultimately be meaningless) and compare them to the rest of the literature to get as clear a picture as possible. I takes a great deal of training and expertise to do this, with those than finally make the decisions having been immersed and kept up to data on the literature for many years if not decades.

Expertise is elitist by it’s nature as there are people that are objectively better at the synthesising of the literature than others. This means that not just anyone gets to ‘have a crack at it’, I know my limitations and know how hard it is to become an expert. As such, I am very happy to take the advice of the health system on this over the content that I come across online.