The first paragraph shows no logical thinking was used when creating this.

The first place the virus shows up is before it's mutated, before it's evolved, in it's original form.
The last place it shows up is after it's mutated, after it's sampled the diversity of races, differences in immune systems and changed into different forms in order to infect as many as possible.

Sometimes I'm on a planet with an apex species that has virtually no ability to utilize their massive brains. A mind is a terrible thing to waste.