Abuse of Power
The theme for The Fever Code is that people with large amounts of power tend to abuse that power. Many examples of this theme are evident in this book.
So, in this world, WICKED has all of the power since their main motive is to cure the disease that destroyed their world. They take what they want for their research and nobody is powerful enough to stop them. In the book WICKED finds immune children and take them from their families with or without permission from the parents.
But wait that’s not far enough for WICKED. After WICKED takes the immune kids from their families, they start to conduct tests and isolate the children to get maximum results. Then after a couple years of preparation, WICKED throws the kids into the Maze trials.
After all of this and more, I can conclude that the more power one has, the more corrupt them can become.