This is the deadliest virus on our planet… but, human cells are safe. The deadliest virus on our planet only feasts on bacteria, aptly named: Bacteriophage - bacteria eater. Now that our antibiotics aren't as effective against the ever-evolving multiresistant bacteria, phages are a promising tool for defending ourselves in the future. They are highly specialized so they only attack the bacteria they’re supposed to, reducing the side effects of a treatment.