The human virome is essentially your fourth genome. It interacts directly and indirectly with your other three genomes. Your virome involves the trillions of viruses that are believed to far outnumber both the cells and the microbes within your body. According to authors Enriques and Gullans, there are an estimated 10 billion bacteria in a liter of seawater, there are also 100 billion viruses playing with them. Even more may live inside the soil and dirt that cover your hands. Viruses, and there are at least ten times more of them inside you at any given time than there are bacteria. They live in your intestines, mouths, lungs, skin, and blood, continuously shuttling in and out of your body. Sneeze once, uncovered, and 40,000 droplets, each containing up to 200 million individual viruses, fly across the room at speeds exceeding 200 miles per hour. More tomorrow.