Great video by a Dr. with a Masters in Public Health who has explained this very professionally and puts things in great perspective.
https://www.facebook.com/nicole.tyreturnbo/videos/10221888243736112/UzpfSTEwMDAwNDEwNjIzODA2MzoyMDMxOTE1ODkwMjg4N
https://www.facebook.com/nicole.tyreturnbo/videos/10221888243736112/UzpfSTEwMDAwNDEwNjIzODA2MzoyMDMxOTE1ODkwMjg4N