(layman but web searches haven't yet answered my question well)

Both the virus and the vaccine may have long-term unknown effects. Of course, we simply don't have the data in this case.

In prior viruses and vaccines, are there examples in which similar viruses and/or vaccines had much different short-term effects than long-term effects?

For example, virus A or vaccine X had minor short-term effects and side effects, but drastically different long-term (multi-year) effects?

Or, is each virus and vaccine so different that my question is not a good question to begin with?