> I thought the marshmallow test was in the other direction - the millions of people who acquired natural immunity through infection, but "grabbed the marshmall

> I thought the marshmallow test was in the other direction - the millions of people who acquired natural immunity through infection, but "grabbed the marshmallow" in the form of the vaccine. What will the long term effects be? We don't know. Assuming that natural immunity is still up to date and kicking, then there shouldn't be any issues with this. After all, the body should recognise and then proceed to battle the vaccine. You may experience symptoms, but at least the way I understood it these are short term, not in the long run. On the other hand, if the natural immunity has weakened then this is good training. So really, as far as I can see there is no reason to ever not take a vaccine unless you had an infection just a short while ago