Paradise Orange Evolve 

A group of lucky survivors, led by Maryville's college librarian, are immune to an infection unleashed by vicious aliens who want to wipe out humanity, colonize the planet, and replace Earth's verdure with their alien orange thicket. The survivors travel across the country to find their family members who may still be alive. They discover that the communities that still exist, such as the one ruled by the King of New York, may be undesirable and even life-threatening. At the same time, two Vecto scientists search for the survivors to validate the results of the alien's human experiment.

Continue the saga with the second book in the trilogy, Paradise Orange: Evolve

It is available on Amazon.

https://www.Amazon.com: Paradise Orange: Evolve: 9798832443744: Stogryn, Stephen, Stogryn, Shelby: Books