There is not much doubt that some vaccines in some people can trigger CFS. However what we do not know is how many will get CFS from severe infections because they were not vaccinated. Had the measles vaccine existed when I was a child I might not have become sick. Vaccines are tricky things, and they can cause harm, but they also prevent a great deal of harm. The specific vaccine, for a specific patient, has to be considered when thinking about potential harm.
Coxsackie virus triggers are common in ME and CFS. Its also known that some strains of Coxsackie, in mice, can induce a polio like syndrome. However this is a different virus family, and we need to treat it as such.
There is also a correlation between polio outbreaks and ME outbreaks for last century. However not all polio outbreaks resulted in ME, and not all ME outbreaks are linked to polio. While I have speculated about a link for maybe twenty years now, its one thing to call it speculation and another to say its certain. I wouldn't want to do that with current evidence. However I wouldn't want to completely dismiss it either, and I would treat it as a research question at most.
You can't just interchange polio with Coxsackie in an argument. They are not the same. You might be able to draw some analogies, then speculate, then pose research questions which would need to be investigated.
I consider it likely that a Coxsackie infection triggered my ME from mild to moderate in 1985, for a few reasons I shan't mention here.
We know this virus can trigger ME. We know that some research shows possible persistent gut infection. We do not know Coxsackie is ME.
I would like to add that, if I recall correctly, paralysis was an uncommon symptom of polio. Very few ME patients develop full paralysis. We hear of a few isolated cases, though I am not aware of any study investigating this epidemiologically. What I am unsure of, and have not investigated, is the full range of polio symptoms aside from paralysis. I do know there was enough similarity that it was long speculated that post polio syndrome is ME. However my suspicion is that its more likely that ME includes post polio syndrome, rather than the other way around. ME appears, at least for now, to be in part a post pathogen syndrome with wide etiology.
I find the speculation about Coxsackie operating in the missing niche that used to be occupied by polio to be a bit of a leap. Its not impossible, but its beyond even idle speculation. I have considered this in the past myself, and I do not find any persuasive evidence that this can occur. It can happen with some strains of bacteria due to how they communicate, or outright competition, but I don't think viruses communicate like that. However there is some suggestion that viral responses may change depending on existing co-infections, so I cannot completely rule it out either.
PS It might help to think of bacteria as an ecology, but viruses swarm. They are more like locusts than most things in an ecology.
