As millions of Americans struggle to recover from covid and millions more scramble for the protection offered by vaccines, U.S. health officials may be overlooking an unsettling subgroup of survivors: those who get infected more than once. Identifying how common reinfection is among people who contracted covid — as well as how quickly they become vulnerable and why — carries important implications for our understanding of immunity and the nation’s efforts to devise an effective vaccination program.
But scientists’ understanding of reinfection has been constrained by the limited number of U.S. labs that retain covid testing samples or perform genetic sequencing. A KHN review of surveillance efforts finds that many U.S. states aren’t rigorously tracking or investigating suspected cases of reinfection.
KHN sent queries about reinfection surveillance to all 50 states and the District of Columbia. Of 24 responses, fewer than half provided details about suspected or confirmed reinfection cases. Where officials said they’re actively monitoring for reinfection, they have found far more potential cases than previously anticipated.
“A lot of patients ask, ‘How long do I have to worry about getting covid again?’” [infectious disease physician Edgar Sanchez] said. “I literally tell them this: ‘You are probably safe for a few weeks, maybe even up to a couple of months, but beyond that, it’s really unclear.’”