New COVID-19 testing method can potentially catch infections just hours after exposure

New molecular testing method in early stages of development by Flatiron Institute researchers Computational Biology Center (CCB) can potentially identify COVID-19 infections just hours after exposure with near-perfect accuracy, much earlier than current tests can detect the virus.

According to Frank Zhang, CCB researcher and lead author of the study, who was reported on Monday Cell report methodscurrent COVID-19 testing “Rely on the same principle, that you have accumulated a detectable amount of viral material, for example, in your nose. This poses a challenge when it’s early in the time window of infection and you haven’t accumulated much viral material, or you’re asymptomatic.

Instead of detecting the viral material itself, the new method developed by the CCB team sought to detect markers of how the body mounts an immune response when infected with SARS-CoV-2. They note that when the viral onslaught on the body begins, specific genes turn on and segments of those genes produce mRNA that signals the construction of specific proteins. By understanding how this particular mix of mRNA molecules helps encode proteins to fight the virus, the team was able to identify when the body mounts an immune response based on the relative abundance of these mRNA molecules. According to the researchers, this is the first time that this approach has been used to diagnose an infectious disease.

To develop their testing method, the CCB team used blood samples from a 2020 study of United States Marine Corps recruits collected before and after the recruits contracted COVID-19. From these samples, the researchers’ computational method uncovered more than 1,000 disease-associated mRNA variant ratio changes. When researchers took this approach to real-world blood samples, it was found to be 98.4% accurate in detecting SARS-CoV-2 infection – even in people. asymptomatic – marked improvement in antigen tests found to be only about 605 accurate.

Zhang, who is now an assistant professor at Cedars-Sinai Medical Center, noted that it was surprising that their test worked so well and showed promise as a complementary testing approach to gold standard PCR tests.

But there is still work to be done, he said. For this initial research, the team only tested blood samples as opposed to the more common and easier to collect nasal swabs used for existing tests. Furthermore, while “the computational framework of RNA splicing opens a promising avenue for host-response diagnosis of infection”, the team noted that further work is needed. to ensure that it can distinguish between the body’s response to SARS-CoV-2 and infections caused by other viruses.

The team hopes to overcome this hurdle by building on the research of other teams who have made progress in creating tests that seek to identify only genes that activate during an infection. Zhang thinks these tests could easily add his team’s computational approach to make these tests even more efficient. “Anything they can do, we can probably explore and join forces,” said Zhang, who includes a method of detecting infection within hours of exposure to the virus.