Statistical analysis
Geometric mean concentrations (GMCs) and 95% CIs were calculated for anti-S IgG, anti-RBD IgG, and ADCC IgG. Pseudovirus NAb geometric mean titres (GMTs) and 95% CIs were evaluated at day 28, day 42, and day 180. Titres below the lower limit of detection (LoD) were given the value of half the LoD. We calculated 95% CIs for GMCs or GMTs by back transforming the 95% CI for log antibody concentrations or titres.We analysed the proportion of individuals with an anti-S, anti-RBD IgG concentration and PSVN NAb titre above the threshold predictive of 80% risk reduction of symptomatic COVID19 (referred to as putative risk reduction threshold [PRRT]) due to wild type and mainly alpha VOC using the approach described by Feng and colleagues for the AZD1222 vaccine.The increase factor between day 0 and day 28 of NAb titres was evaluated by presenting the geometric mean of the ratio of NAb titres at day 28 and day 0. The geometric mean of the ratio of Nab titres of D6414G and each variant was calculated at all timepoints. The 95% CI for geometric mean ratios were calculated by back transforming the 95% CI for the log of the ratio.The percentage reduction in geometric means of NAb titres between day 42 and day 180 are calculated as subtracting the geometric mean of the ratio of NAb titres at day 180 and day 42 from one. 95% CI for percentage reduction in geometric means were calculated by subtracting the 95% CI for the geometric mean ratio from one.Comparisons of demographic and clinical features between baseline anti-N IgG seropositive and seronegative individuals were done by means of Wilcoxon rank sum test for quantitative variables and χThis is a descriptive study and no considerations were taken into account for multiple testing or adjustment for differences in demographics between the two groups.The COV005 study is registered with 