“Every infectious disease that spreads has a certain mathematical way of spreading it,” explains Schlozman. Viruses that are transmitted through bites, such as the rabies virus, don’t spread quickly because they can be isolated.
Meanwhile, the spread of viruses that are transmitted through the air, such as influenza, can spread quickly in an area. “All the pandemics we experience on Earth typically spread through the air,” said Schlozman. Zombies do exist, but not in humans but in other creatures, namely ants, especially tropical wood ants.
It Turns Out That Zombies Exist In The Real World, This Is The Scientific Explanation
source