Detailed in a new report in the journal Science, researchers have developed a new test that can determine every virus that has ever affected you — and all it takes is a single drop of blood. As you would expect, the process is fairly complex, but conceptually it’s fairly easy to understand. Here’s a very basic overview of how it works.
Whenever your body is infected with a virus, your immune system jumps into action, setting loose a team of special white blood cells called T and B lymphocytes. Some T cells are capable of detecting and killing viruses, but others serve as “helpers” for B cells, which then produce antibodies. Antibodies, as you might remember from high school biology class, are the little y-shaped proteins that tag invading cells for destruction.
After your body conquers the virus and clears it from your system, some of these specialist T and B cells stay around to keep a “memory” of the destroyed virus, so that your body can more easily identify it in the event that it should ever come back. The newly-developed technique basically teases out these memories, and uses them to determine all the viruses a person has ever been infected with.
While you might not care to know all the illnesses you’ve ever had, that kind of information is invaluable to virologists. Armed with this data, infectious disease researchers could do amazing things, like track patterns of disease across various populations, help scientists compare immune responses in old and young people, or see how the same virus affects people in different parts of the world. If performed on old blood samples (which labs often store from previous studies), the technique could even be used to help us learn about how viruses spread in the past.
The process is still in the experimental phase, but scientists are already highly optimistic about the potential impact it will have. “This will be a treasure trove for communicable disease epidemiology,” infectious disease expert Dr. William Schaffner of Vanderbilt University told the New York Times. “It will be like the introduction of the electron microscope. It will allow us to have more resolution at a micro level.”
It’s worth noting, however, that the test isn’t quite ready for primetime just yet. It’s still in the experiemental stages right now, and despite the fact that it’s already farily cheap to administer (about $25 per test), it’s far from perfect. The test still takes weeks to complete, and it can still miss some viruses, including past infections that the body’s immune system is only responding to on a very low level.
Even so, it’s still a very exciting development. With a few more trials and careful testing, the hope is to streamline the test and make it available to the general public. In a couple years, you might just be able to request your “virus history” at your next checkup.
