“If there were, would we ever hear about them?”
I would think more than zero would respond. It would be a massive story, for any doctor/scientist or reporter.
“This is akin to the typical response I hear from very average people regarding anything strange, especially in the last two years: “If that were true, we would have seen it on the news by now!””
Maybe someday I can be above “very average people” in your eyes...