COVID is persistent. We’ve known for years that other coronaviruses, like SARS, can persist in your body long after initial infection. This is likely a byproduct of their evolutionary history; they evolved to spread through bat populations and survive bats’ unique immune systems. Bats are very long-lived for their size, potentially living for decades, even with multiple different infections quietly simmering inside them. However, in humans, these viruses’ tactics for suppressing a well-regulated bat immune system present a form of overwhelming force, which wreaks havoc on our bodies.