An easy-to-use test, which uses the same type of lateral flow technology as most rapid antigen tests for COVID-19, measures the level of neutralizing antibodies that target the SARS-CoV-2 virus in a blood sample. This kind of test could help people determine what kind of precautions they should take against COVID infection, such as getting an additional booster shot.
The test is designed so that different viral spike proteins can be swapped in, allowing it to be modified to detect immunity against any existing or future variant of SARS-CoV-2, the researchers say. The device can detect the presence of antibodies that block the SARS-CoV-2 receptor binding domain (RBD) from binding to ACE2, the human receptor that the virus uses to infect cells.
The first step in the test is to mix human blood samples with viral RBD protein that has been labeled with tiny gold particles that can be visualized when bound to a paper strip. After allowing time for antibodies in the sample to interact with the viral protein, a few drops of the sample are placed on a test strip embedded with two test lines.
The researchers have filed for a patent on the technology and are now hoping to partner with a diagnostic company that could manufacture the devices and seek FDA approval.