- The new test, known as VirScan, works by screening the blood for antibodies against any of the 206 species of viruses known to infect humans.
- The immune system, which churns out specific antibodies when it encounters a virus, can continue to produce those antibodies decades after an infection subsides. VirScan detects those antibodies and uses them as a window in time to create a blueprint of nearly every virus an individual has encountered.
- During initial tests, they found that the average person has been exposed to 10 of the 206 different species of known viruses — though some people showed exposure to more than double that number.