When a comment leads with a provable falsehood, that "the" COVID vax (already a rampant simplification) "only" reduces risk of a bad case, and that, by implication, there's no reduction in transmission or reduction in duration or reduction in severity of mild cases, there's not much charity to be given.

Using your analogy, it's like if someone questioned the claimed efficiency of solar panels "given the Earth is flat after all". It shows a fundamental divergence from observed fact and science.