Our bodies are home to trillions of microbes that apparently help it function.
Unexpectedly, these mice have been found to have serious bone and muscular issues. Their bodies never developed properly- because they’ve never been sick.
This is surprising and yet not really so when you think about vaccines. All vaccinations are is a bit of the virus it’s supposed to protect you from.
Our bodies attack those microbes and develope anti-bodies that help fight off future infections.
Evolution has made viruses and disease relevant to growing our bodies. If we’re kept from disease, our bodies don’t grow properly.
Life works in mysterious ways.