Earlier this week, the world's first confirmed case of someone reinfected with COVID-19 emerged out of Hong Kong. Now, the US claims its first case. Per CNN, researchers from the University of Nevada-Reno School of Medicine and the Nevada State Public Health Laboratory detail the case of a 25-year-old patient who started showing signs of the coronavirus in late March, including sore throat, cough, headache, and nausea. He was diagnosed with COVID-19 in mid-April and, after a few weeks, recovered, testing negative twice. Then, in late May, he came down with more serious symptoms, and by early June he was hospitalized and put on oxygen. His COVID-19 test came up positive. When the scientists tested the man's genetic material, it indicated he'd been infected with two different strains of the virus. "Having had it doesn't mean you can't get it again, that's what this shows," Dr. Mark Pandori, study co-author and head of the NSPHL, tells ABC News.
There's one big difference between this case and the one out of Hong Kong. In the latter, the patient was asymptomatic the second time around, seeming to suggest that reinfection may cause a milder case of the virus. The Nevada patient, however, was sicker the second time than he was the first time. The scientists say the man didn't have any known underlying immunity issues that may have upped his reinfection risk, per Newsweek. The Nevada case report hasn't yet been peer reviewed, and the scientists warn not to generalize based on just this one report, but they say it adds yet another clue on how the virus works, how effective vaccines may be, and even whether herd immunity is achievable. "There's no invulnerability here," Pandori tells ABC. "Whether you've had this infection before or whether perhaps in the future [you get] vaccinated, there won't be such a thing as invulnerability." (Read more coronavirus stories.)