[Question] What is the literature on effects of vaccines on the central nervous system?

I saw some evidence from the recent covid-19 threads that some viruses permanently stay in the brain and cause some damage; This has made me wonder how effective (or alternatively unsafe) vaccines are (flu vaccines in particular).


Here is one study on h5n1 on mice:

https://​​www.jneurosci.org/​​content/​​32/​​5/​​1545.short