Fig. 3: Symptomatic vaccine effectiveness (symptomatic VE) estimates across testing scenarios, study designs, and sampling periods, and cumulative proportions of symptomatic infections by vaccination status.
Symptomatic VE estimates derived from the retrospective cohort design (VERR, (a) and (b)) and the retrospective test-negative design (VEOR, (e) and (f)) are shown, along with the cumulative proportions of symptomatic infections by vaccination status ((c) and (d)). Panels show results under two levels of vaccine efficacy against susceptibility: higher (0.55) and lower (0.1), which represent the true symptomatic VE (grey dashed line). VERR and VEOR were calculated across three testing scenarios (green): equal testing by vaccination status, moderately unequal testing (vaccinated with 1.76 times higher testing), and highly unequal testing (vaccinated with 2.36 times higher testing). Each time point corresponds to symptomatic VE estimates from studies conducted at that time during the epidemic. The cumulative proportions of symptomatic infection represent the cumulative level of symptomatic infection for unvaccinated (yellow) and vaccinated (dark gold). Central lines depict the median, and shaded regions indicate the 2.5th–97.5th percentile range across n = 100 epidemic realisations.
