its more complex and nuanced than this. I had thought that the chickenpox vaccine gave you a higher chance of shingles in later life. However that appears to be the opposite of what actually happens.
The crucial thing is that its dependent on the vaccine and the thing infecting you.
For example the BCG jab which protects against TB is wild. Its a live vaccine that has been evolving, got lost once, and its kinda black magic. In older people it has a ~33% efficacy. its much more effective in babies and children though.
However we've got to the point that TB is so rare in the UK that targeted vaccination is more than enough to keep it under control.
With covid, we need to make sure that when people get it, they don't get seriously ill. Ideally they wont get it at all, but alas thats not the case, the vaccines are not effective enough for that against this variant.
I assume that altering the mrna vaccines would have a similar speed as the annual flu vaccine, so changes for new variants would require less development time.
But as someone pointed out, if you have a vaccine, and you get covid, te seems reasonable to assume that you will have a better immunity.
Also with just 8 cases out 32k, it seems a small dataset to draw conclusions on.