Dr. Anthony Fauci on Friday said it’s possible that Americans could eventually carry around certificates of immunity to the coronavirus once proper testing is widespread enough.“That’s possible,†Dr. Fauci, director of the National Institute of Allergy and Infectious Diseases, said on CNN’s “New Day.â€â€œIt’s one of those things that we talk about when we want to make sure that we know who the vulnerable people are and not,†he said. “This is something that’s being discussed. I think it might actually have some merit.â€Sen. Bill Cassidy, Louisiana Republican, has pitched the idea of an immunity registry to document people no longer believed to be...