COVID-19: Is there a role for Western blots and skin testing for determining immunity and development of a vaccine?

Infection with the virus, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) stimulates an immune response which can serve as a marker for current or past exposure to this pathogen, and possibly for resistance to re-infection. This response to COVID-19 can be monitored based on the production of antibodies, and thus, serologic tests have become available for diagnostic purposes. Despite progress in this area, concerns have been raised that too many of the commercially available serologic detection systems are not completely reliable. To address this issue, Western blots should be considered for confirming a positive or borderline-positive result from a screening test, such as an ELISA. An additional benefit of Western blots would be to identify antigens that could form the basis for developing a vaccine. Little is known about the cell-mediated immune response against COVID-19. One way to address this would be to use skin testing to measure the delayed-type hypersensitivity response in patients recovering from COVID-19.