We also know that the usual mechanism for bad reactions to vaccines is allergic reaction, which is easily observed on a short timescale, and basically doesn't happen with the covid vaccines.
The question is really fundamentally simple for a massive vaccination campaign
Expected injury rates as a % of the population
Actual / Reported injury rates as a % of the population
Even while accounting for the low likelihood of even receiving reports of things.
We already know that some of the injury reports coming in have been independently verified by other nation's health departments. After all, there is a reason for some of the vaccine pauses among the young and healthy in the nordic countries.
Those would not be in VAERS. At all.
Everyone, go get vaccinated, please.
A friend of mine that happens to be a medical professional in a European country told me of the clotting related issues starting to show up in their own numbers far in advance of it being likewise confirmed in VAERS too.
That is why we know about these issues.
Country A and Country B have problems that show up, they ask which vaccine, which vector, etc, and they draw conclusions.
Reason 5 - Quality of vaccine, freshness, poor QA, defective dose
I think this is a likely concern in some countries. The vaccines are challenging to transport and properly keep stable and manufacturing of them happens in many places and was put in place and scaled up very quickly, quality control could be an issue, same as proper transportation and storage.
I would honestly give this one a 5% chance.