Traditional blood tests, known as ELISA assays, are only able detect one pathogen at a time and scientists have yet to develop ELISA assays against all viruses. In comparison, Virscan can simultaneously test for more than a thousand different strains of viruses that have previously or currently infected a person.
“What makes this so unique is the scale: right now, a physician needs to guess what virus might be at play and individually test for it. With VirScan, we can look for virtually all viruses, even rare ones, with a single test,” says corresponding author Stephen Elledge, in a statement.
For the study, Elledge and his team developed a large number of peptides, which are short protein fragments derived from viruses, to find evidence for previous and current viral exposure. This screening technique was tested on 569 people from Peru, the United States, South Africa and Thailand.
The study, published in Science, found that over their lifetimes, participants had been exposed to an average of 10 viral species. While rates of viral exposure differed by age, geographic location and HIV status, researchers were still able to identify a small number of peptides across the vast majority of participants. Researchers suggest this pattern is important for our understanding of the immune system, as many people seem to be exposed to the same peptides.
Virscan could also be used to investigate relationships between a previous exposure to a virus and the development of a disease further down the line. A correlation between the Epstein-Barr virus, a common virus in the study, and certain cancer has previously been established. Researchers hope to use Virscan to fill in the blanks and find more correlations between specific viruses and developments of disease.
"A viral infection can leave behind an indelible footprint on the immune system," said Elledge, "Having a simple, reproducible method like VirScan may help us generate new hypotheses and understand the interplay between the virome and the host's immune system, with implications for a variety of diseases.”