Scientists stress that just because someone has recovered from Covid-19 and produced antibodies to the coronavirus does not mean they are protected from contracting it a second time. No one’s yet proven that.
That, then, leaves open the question: What does immunity look like?
Experts anticipate an initial coronavirus infection will lend people some level of immunity for some amount of time. But they still don’t know what potpourri of antibodies, cells, and other markers in a person’s blood will signify that protection. And determining those “correlates of protection” is crucial both so individuals can know if they are again at risk, and so researchers can understand how well potential vaccines work, how long they last, and how to accelerate their development.