SOLVED. Sci-fi - 2010s - Two boys, one super smart grew up to be a scientist who made human-creatures to replace all the humans. They glowed and vibrated. Spoilers ahead. [s]

[Kathleen]

YA Sci-fi - 2010s - Two boys grew up together, one super smart. He grew up to be a scientist who made human-like creatures to replace all the humans. They glowed and vibrated. He vaccinated the protagonist and left him to care for them, while he killed every other human with a virus.

They both liked a specific girl online, and the smart kid had pictures of her saved on his computer. The protagonist found a file hidden in the eye of the girl in one of these pictures that basically detailed the scientist's plans to end humanity and replace them with these human-like creatures who vibrated to heal each other and glowed to signify if they were open to mating. The protagonist meets the girl from the photos at some point, but she says she doesn't remember taking the pictures.

The scientist friend vaccinates the protagonist kinda against his will, but it turns out to be the only vaccination ever against a disease the scientist is planning to release to the whole world, to kill every human being. He leaves his friend in charge of these human-creatures, to help them repopulate the world.

[Andy Phillips]

This is a long shot as I haven't read it in ages, but maybe Oryx and Crake.

[Kathleen]

Andy Phillips wrote: "This is a long shot as I haven't read it in ages, but maybe Oryx and Crake."

YES! That's it, thank you!