If you expect natural selection to turn #Covid into a mild virus...think again. "We've been exposed to measles for at least 900 years, but it has never evolved to become mild. We had smallpox for 1,700 years -- never became mild. Rabies has been around for 2,000 years -- still not mild. Hepatitis B for 5,000 years -- not mild" Looks like COVID will be around for a while. #disease #nature #virus #health https://www.nature.com/articles/d41586-020-02083-0