Bats cope with myriad viruses, including the one causing Covid-19, with few ill effects. Scientists are probing their immune systems to fathom how they do it. The answers might help infected people, too.
Antibodies should indicate if someone has had an infection in the past. But the promise of “immunity testing” is plagued by uncertainty about how the immune system responds to the coronavirus, as well as concerns about the tests’ accuracy.
The body’s defenses lose flexibility and diversity over time, and protective responses to vaccines weaken as well. Scientists are working on ways to boost seniors’ protections against influenza, the novel coronavirus and other pathogens.