This is a false analogy, because COVID isn't nearly as dangerous as polio, especially to children, and the COVID vaccines aren't nearly as effective as the polio vaccines.
Best I can find right now, there have been roughly 750 deaths of children in the US from COVID resulting from roughly 9.335 million cases, for a CFR of roughly 0.008%, slightly under half that of polio for the same age group. However, CFR overall is roughly 1.189% in the US for all age groups currently (879,971 deaths/74,037,216 cases), over 100x the rate of polio for all age groups.
That's not including long term effects from COVID with people having scarred lungs / damaged organs, new research indicating increased diabetes rates in children who have had COVID, new research finding long term micro blood clots even in asymptomatic cases, etc.