The ultimate goal of the new and emerging SARS-CoV-2 antibody tests is to determine when and how we can safely get back to work and restart our stalled economies. While knowing how many people are sick is valuable in tracking the rate of disease spread and identifying people who need to isolate or seek treatment, it misses out on telling us who has had the virus and has recovered (or may have not been symptomatic at all). The idea is that people with antibodies may be protected from (re-)infection and are therefore safe to return to “normal” life. (caveats are that these antibodies are actually protective and will last, conferring immunity).
A good article discussing what antibodies are and how these tests operate was recently published in USA Today. The form of many of these tests is very similar to home pregnancy tests (lateral flow ELISAs), enabling quick, rapid results with no special training to perform.
Eventually, once enough people have been exposed to the virus and recovered or been vaccinated against the virus (probably early next year), then we will have herd immunity sufficient to protect the vulnerable people around us from being exposed to a life-threatening illness.
In the meantime, we’ll probably have to be content with a ‘new normal’ of living in a way that doesn’t prevent the spread of infection but limits it to a level that our hospitals can bear.