Fig. 2: Neutralising antibody levels to ancestral SARS-CoV-2 in cohort 3-28d-8m (adults aged 60 years and older).
From: Six-month follow-up of a booster dose of CoronaVac in two single-centre phase 2 clinical trials
The number of participants for each group (placebo group, pink; 1.5 μg group, yellow; 3 μg group, green; 6 μg group, blue) at each visit included in the analysis is provided below the bars. Dots are reciprocal neutralising antibody titres for individuals in the per-protocol population. Numbers above the bars are geometric mean titres (GMTs), and error bars indicate 95% CIs. GMTs and corresponding 95% CIs were calculated on the basis of standard normal distributions of log-transformed antibody titres. Numbers above the short horizontal lines are p values for comparisons between the 1.5 μg group, the 3 μg group and the 6 μg group using ANOVA models with log-transformation. Bonferroni correction done as a post hoc test if the variance was significant. Only P values indicating significant differences are marked. Titres lower than the limit of detection (1:4) are presented as half the limit of detection. The dotted horizontal line represents the protective threshold (1:33).
