Sars Virus

There are 200 letters in the genetic code for the receptor binding domain, and there are 20 possible amino acids in each that you could change. The standard for sars one was that the first time it touched humans, it only had 15 % of the changes it needed to become a pandemic. So we have a virus that is absolutely perfected for human interaction, but it's never seen a human in the community. In wohan, 36, 36 thousand blood bank samples were tested, and none were positive for infection.