Volume 28, Number 1—January 2022
    
    Research
Mask Effectiveness for Preventing Secondary Cases of COVID-19, Johnson County, Iowa, USA
Figure 2

Figure 2. Number of contacts with test results during study of mask effectiveness for preventing secondary cases of coronavirus disease, Johnson County, Iowa, USA, October 23, 2020–February 28, 2021.
Page created: October 12, 2021
                            Page updated: December 20, 2021
                            Page reviewed: December 20, 2021
        
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