Antibody responses to SARS-CoV-2 in patients with COVID-19

TLDR

We assessed acute antibody responses in 285 COVID‑19 patients. Within 19 days all patients tested positive for IgG, with IgG and IgM seroconversion occurring simultaneously or sequentially and titers plateauing within six days, and serology can aid diagnosis when RT‑PCR is negative and detect asymptomatic infections.

Abstract

We report acute antibody responses to SARS-CoV-2 in 285 patients with COVID-19. Within 19 days after symptom onset, 100% of patients tested positive for antiviral immunoglobulin-G (IgG). Seroconversion for IgG and IgM occurred simultaneously or sequentially. Both IgG and IgM titers plateaued within 6 days after seroconversion. Serological testing may be helpful for the diagnosis of suspected patients with negative RT-PCR results and for the identification of asymptomatic infections.