Fig. 5: Antibody responses in a HCW cohort.
a, ID50 values plotted against the time POS at which sera were collected. Each line represents one individual (n = 37). ID50 was measured using HIV-1-based viral particles pseudotyped with the S glycoprotein of SARS-CoV-2. Asymptomatic individuals are shown in green, symptomatic individuals in black and HCWs with PCR-confirmed SARS-CoV-2 infection in red (for comparison). The vertical dotted line represents day 0 POS. Of seropositive individuals, 80.6% (25/31) recorded COVID-19-compatible symptoms (including fever, cough and anosmia) since 1 February 2020, and 19.4% (6/31) reported none. A subset of neutralization experiments (n = 10) were conducted twice, yielding similar results. ID50 values for the remaining samples were measured once. b, Comparison of the peak ID50 between asymptomatic individuals (n = 10, includes 7 HCW and 3 hospital patients), HCWs (n = 24 symptomatic HCWs with no PCR test), and PCR+ individuals with severity either 0–3 (n = 28) or 4/5 (n = 32). The two PCR+ individuals, who were sampled at early timepoints (<8 d POS) and did not seroconvert, were not included in this analysis. c, ID50 at peak neutralization is plotted with the donor-matched ID50 at the last timepoint sera were collected. The dotted line represents the cut-off (1:50) for the SARS-CoV-2-pseudovirus neutralization assay. Asymptomatic donors are shown in green and symptomatic donors in black.
