Atheists, the death penalty and abortion...

[festive1]

Isn't that evident?
When it can function by it self, without the need for a host.

Then by your defininition, newborn children and comatose patients on lifesupport should also be considered parasites.

No. Newborns and the comatose simply need food and basic care. Infants born prematurely do not even possess the skills of suckling and swallowing without aspirating. They cannot regulate their body temperature. They have no immune system. Very different from a newborn or someone in a coma.