Longitudinal dynamics of the neutralizing antibody response to SARS-CoV-2 infection

Wang, Kai; Long, Quan-Xin; Deng, Hai-Jun; Hu, Jie; Gao, Qing-Zhu; Zhang, Gui-Ji; He, Chang-Long; Huang, Lu-Yi; Hu, Jie-Li; Chen, Juan; Tang, Ni; Huang, Ai-Long

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a global pandemic with no licensed vaccine or specific antiviral agents for therapy. Little is known about the longitudinal dynamics of SARS-CoV-2-specific neutralizing antibodies (NAbs) in COVID-19 patients. METHODS: Blood samples (n=173) were collected from 30 COVID-19 patients over a 3-month period after symptom onset and analyzed for SARS-CoV-2-specific NAbs, using the lentiviral pseudotype assay, coincident with the levels of IgG and proinflammatory cytokines. RESULTS: SARS-CoV-2-specific NAb titers were low for the first 7–10 d after symptom onset and increased after 2–3 weeks. The median peak time for NAbs was 33 d (IQR 24–59 d) after symptom onset. NAb titers in 93·3% (28/30) of the patients declined gradually over the 3-month study period, with a median decrease of 34·8% (IQR 19·6–42·4%). NAb titers increased over time in parallel with the rise in IgG antibody levels, correlating well at week 3 (r = 0·41, p & 0·05). The NAb titers also demonstrated a significant positive correlation with levels of plasma proinflammatory cytokines, including SCF, TRAIL, and M-CSF. CONCLUSIONS: These data provide useful information regarding dynamic changes in NAbs in COVID-19 patients during the acute and convalescent phases.