The screening methods used in the study proved to be reliable and inexpensive alternatives to the current standard used in testing.
A recent study conducted by investigators from the University of Michigan, Michigan Medicine has demonstrated that antibody testing, even rapid screening methods like finger pricks, can be effective testing tools and can predict a prior COVID-19 infection.
Results from the study were published in the journal PLOS ONE.
"For a long time, people were very worried that people with mild COVID did not make immune responses," Charles Schuler, a clinical assistant professor of allergy and immunology at Michigan Medicine said. "This should give people confidence that the tests that are available to them aren't just random number generators. They're actually giving them something useful."
For the study, investigators examined lateral flow assays, in which a drop of blood or serum is placed on a piece of filter paper that changes color and indicates if antibodies are present. They analyzed samples from over 500 participants, of which 104 had a history of COVID-19 infection and a positive PCR test.
Findings from the study showed that 2 rapid tests agreed with positive lab results between 93 and 97 percent of the time, despite some false positive. This indicates that the rapid screens can predict infections with basically the same precision as antibody tests that are conducted in a laboratory.
“I was actually surprised at how well some of these tests did because it's a very different experiment," Schuler said. "If you have a patient at a clinic that does not have a lab on site, we could find out if you had COVID before and we can do it now and we can do it at low cost."
The team behind the study plans to continue evaluating subjects with focus on novel tools. They hope to answer more questions pertaining to antibodies and the protection they offer.
"This is a down payment on, hopefully, a lot of great future data" Schuler said.. "While antibodies may or may not tell you how immunity happens, they might tell you about reinfection risk. That is the functional clinical significance that we need to know as soon as possible."