Serologic Responses in Healthy Adult with SARS-CoV-2 Reinfection, Hong Kong, August 2020

Abstract

In March 2020, mild signs and symptoms of coronavirus disease developed in a healthy 33-year-old man in Hong Kong. His first infection did not produce virus neutralizing antibodies. In August, he had asymptomatic reinfection, suggesting that persons without a robust neutralizing antibody response might be at risk for reinfection.

Keywords: 2019 novel coronavirus disease; COVID-19; Hong Kong; SARS-CoV-2; antibodies; coronavirus disease; coronaviruses; immune response; reinfection; respiratory infections; serology; severe acute respiratory syndrome coronavirus 2; viruses; zoonoses.

Figure

Timeline of primary infection and reinfection with severe acute respiratory syndrome coronavirus 2, Hong Kong, August, 2020. A) Onset. B) Discharge. C) Clinical follow-up. D) Mandatory testing. Black font indicates data from this investigation; red font indicates data from To et al. (6). C_t, cycle threshold; ELISA-N, enzyme linked immunosorbent assay for N protein; LIPS, luciferase immune precipitation assay; PRNT₅₀, 50% plaque reduction neutralization test titer; RBD, receptor binding domain; RT-PCR, reverse transcription PCR; S/CO, ratio of optical density readings of sample divided by cutoff (ratio of >1.4 considered positive); sVNT, surrogate virus neutralization test; +, positive; –, negative; +/–, borderline.