Blackeye - we all realise that vaccinations that are not...

Blackeye - we all realise that vaccinations that are not properly tested over the 10yr period required risk having long term effects that cannot be known in a few short weeks or even months of testing.
The proof-of-concept is evaluated in the early stages of vaccine discovery, followed by a few years of preclinical studies with lead vaccine candidates prior to clinical testing in humans. Once approved for clinical development, the vaccine will undergo defined stages of clinical testing and monitoring, often over a decade or longer, before being licensed and marketed. Following the introduction of a vaccine on to the market, post market surveillance and safety monitoring continues.
https://www.immune.org.nz/vaccines/vaccine-safety/safety-monitoring

so it takes 10yrs for a vaccine to be passed through the stages of safety monitoring for a valid reason

Public should be told that vaccines may have long term adverse effects
We believe that the public should be fully informed that vaccines, though effective in preventing infections, may have long term adverse effects. An educated public will probably increasingly demand proper safety studies before widespread immunisation. We believe that the outcome of this decision will be the development of safer vaccine technology.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1114674/