Fig. 2.

Antibody response to SARS-CoV-2 spike in negative, asymptomatic and symptomatic participants. Wuhan and Omicron-specific IgG and IgA antibody titres were measured by ELISA and a neutralization assay was performed to quantify neutralization titres. Anti-spike IgG antibody responses for Wuhan (Ai) and Omicron (Aii) peptides. Wuhan (Bi) and Omicron (Bii) neutralization antibody responses. The correlation between anti-spike and neutralising antibodies for Wuhan (Ci) and Omicron (Cii). Salivary Wuhan-specific IgA antibody responses (D). Total N=102 (9 Negative Unvaccinated, 9 Negative Vaccinated, 23 Asymptomatic Unvaccinated, 23 Asymptomatic Vaccinated, 19 Symptomatic Unvaccinated, 19 Symptomatic Vaccinated). For Wuhan IgA, total N=68. Light blue bars = negative participants, dark blue bars = asymptomatic participants, green bars = symptomatic participants. *p<0.05, **p<0.01