I'm not a scientist, but if you were to tell me "this trial shows that substance X is not harmful", I would think ideally it would give substance X to one group and a placebo to the other group. If not possible, it would look after the fact to see group A that received substance X compared to group B that didn't, large enough sample so it would be relatively controlled for extraneous variables. Seems like you would def want to compare the two groups, so what did this study actually do?
Another criticism:
> Among Kennedy’s criticisms of the Danish study are that the analysis excluded children who had died before the age of two. According to Kennedy, this means that the children “most likely to reveal injuries” associated with aluminum exposure were excluded.
From the opinion piece:
> The architects of this study meticulously designed it not to find harm. From the outset, Andersson et al. excluded the very children most likely to reveal injuries associated with high exposures to aluminum adjuvants in childhood vaccines. The exclusion included all children who died before age two, those diagnosed early with respiratory conditions, and an astonishing 34,547 children — 2.8% of the study population — whose vaccination records showed the highest aluminum exposure levels.
I remember looking at some Lending Club loan statistics and their stated yields by Lending Club. I thought it was pretty good at the time. But then I noticed in fine print that from the historical yield calculations, they exclude any loans that defaulted within the first X months. That was not something I expected.
I could see why Lending Club excluded these, but what's the rationale, if true, of excluding some populations from the vaccine trial results?
You are right. Indeed, all vaccines and drugs undergo clinical trials testing for safety first, efficacy then, before being approved for sale and distribution.
The study in question analyzes data that was routinely collected after the vaccine was approved, that is why they didn't do the randomization themselves.
One of these vaccines is DTaP-IPV/Hib aka Pentacel, and the clinical results for it are reported here: https://www.fda.gov/files/vaccines,%20blood%20&%20biologics/...
> The two controlled pivotal safety studies, overall rates of serious adverse events were similar in Pentacel and Control subjects.
(Tested on about 5,000 children younger than two years old and getting two or three doses of the vaccine).
Another trial for that vaccine was recently performed in Japan, also not finding significant rates of adverse events: https://pubmed.ncbi.nlm.nih.gov/32307307/
https://www.theguardian.com/environment/2025/aug/20/slowdown...
Academics don't understand the climate and never did.