coronavirus
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Can my brother be tested now to find out if he had it? And if he did have it, would he now be immune to the virus?

Question: My brother believes he had COVID-19 and got over it. Like so many others, he wasn’t able to get tested. Can he be tested now to find out if he had it? And if he did have it, would he now be immune to the virus?

Answer: Scientists have developed a new antibody test for COVID-19 that will allow for folks like your brother to know whether they were infected with SARS-CoV-2. The tests use an individual’s blood to identify whether their immune system came into contact with the virus. Specifically, the tests check to see if a person has immunological markers — antibodies to SARS-CoV-2 — in their blood. These antibodies are the proteins the immune system makes to neutralize the virus. Mount Sinai in New York has developed one such test. Other such tests are being developed and deployed in Asia and Europe and even a small town in Colorado. I do not know when the tests will be available for broad public use. The beauty of these tests is that they can:

  • Give us a better picture of the COVID-19 infection rate;
  • Identify individuals, especially health workers, who have already been exposed to the virus and are therefore most likely immune and able to safely go back to work. This is especially important for easing health workforce burdens.
  • Help get the economy going as folks who exhibit immunity can presumably stop social distancing;
  • Identify folks who can donate blood plasma for clinical trials of potential therapeutic treatments.

Generally, the presence of antibodies confers immunity. But we are still not sure how long immunity lasts and we are making that generalization based on our understanding of other infectious diseases. We are hopeful it’s the case for COVID-19 too. For more on this issue, please see Q&A of 3/19. What’s one of the more perplexing findings of late is that there is a small group of health workers from Wuhan who had COVID-19, recovered (felt better and tested negative) and are now testing positive again. NPR had a fascinating story on the subject over the weekend. I’m not sure what this means (if anything) for immunity. If nothing less, it highlights just how much we still don’t know.