A new test might be able to detect every virus that someone has ever harboured from a single drop of blood. The test aims to survey all the antibodies floating through a person’s bloodstream to reveal a full history of viral acquaintances. The technique might be useful for identifying current and past health conditions in addition to developing new vaccines.
At the moment, clinicians and researchers investigating a patient for a particular pathogen test the blood for suspected pathogens one by one. Most of these tests check for antibodies, proteins produced by the immune system to fend off foreign invaders, or look out for specific genetic material.
Researchers led by biologist Stephen Elledge of Brigham, Women’s Hospital in Boston and Harvard Medical School aimed to invent a technique capable of diagnosing an entire library of viruses in a person’s body, past and present. The team began by putting together a catalogue of nearly a hundred thousand synthetic protein pieces, each piece representing a segment of a viral pathogen that an antibody in the blood might recognise. The idea is that when these proteins are mixed into a drop of blood, the antibodies may then be isolated and then examined for the fragments they paired up with. Therefore, scientists may then determine which viruses a person has come into contact with throughout their life.
The new innovation, named VirScan, allows scientists to ask questions once thought too challenging. According to Elledge, “You [may] compare groups of people young and old or those with a [condition] and those without and see whether there’s a difference in their viral histories.” This type of investigation may help identify mechanisms that trigger conditions such as diabetes or chronic fatigue syndrome.
VirScan has already been given a work out with over 500 people across the globe, including the US, Thailand, South Africa and Peru. The researchers recently reported in Science that the test was able to detect antibodies for around 10 previous viral encounters in each individual in the sample. Some crept up more often than others, such as the herpes medical condition and those responsible for the common cold. To the team’s surprise, many people developed identical antibodies; researchers assumed people’s immune responses might be more diverse, a notion that might benefit future development of vaccines.
“Before we view this as a definitive definition of what people have [encountered], we need to be sure it’s a comprehensive picture,” explains microbiologist Vincent Racaniello of Columbia University. “Right now, I [am uncertain] it is.” VirScan may need to be tested on more people who may possess antibodies for the norovirus and rotavirus stomach bugs since these antibodies display some tendency to fade out of the immune systems repertoire. The team confesses that at the test’s current stage of development. “We’re still detecting a lot,” admits Racaniello.
VirScan’s true value to the scientific community lies in the breadth of questions it has opened the door to. It may be an innovative tool for probing human’s natural history with viruses and understanding the co-evolutionary arms race between them and mankind.
In the future, researchers aim to increase VirScan’s scale while remaining cost-effective. The technology might also be used as part of routine screening at hospitals and specialist clinics. Elledge explains that, “You [might] give a drop of blood every few years and they [may] run it to see if you have [anything new].” This may productively benefit the prevention of viruses such as hepatitis C, which people are often unaware they have, therefore improving the probability of saving many lives.
How might the technology be used to improve and protect populations from viral outbreaks?