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. 2021 May 26;326(1):1–11. doi: 10.1001/jama.2021.8565

Figure 2. Efficacy of 2 Inactivated Vaccines Against Symptomatic COVID-19.

Figure 2.

A, Cumulative event rates of confirmed symptomatic COVID-19 cases 14 days following a second vaccine dose among participants who received 2 doses, contributed at least 1 efficacy follow-up visit, and had negative polymerase chain reaction test results at enrollment (modified full analysis population-1). Median (interquartile range) observation times for all groups was 77 (47-78) days. B, Cumulative event rates of confirmed symptomatic COVID-19 cases after the first dose among participants who received at least 1 dose, contributed at least 1 efficacy follow-up visit, and had negative polymerase chain reaction test results at enrollment (full analysis population-1). Median (interquartile range) observation times for all the groups were 112 (82-113) days. Alum indicates aluminum hydroxide.