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Effectiveness of Face Mask or Respirator Use in Indoor Public Settings for Prevention of SARS-CoV-2 Infection — California, February–December 2021 | MMWR
World Health Organization (WHO) - When to use mask 😷 • If you are healthy, you only need to wear a mask if you are taking care of a person with suspected
![Cleveland Clinic on Twitter: "Wondering if you should wear a face mask or not? Plus, other frequently asked questions: https://t.co/OKLV2PO5L7 https://t.co/ertJudCgoM" / Twitter Cleveland Clinic on Twitter: "Wondering if you should wear a face mask or not? Plus, other frequently asked questions: https://t.co/OKLV2PO5L7 https://t.co/ertJudCgoM" / Twitter](https://pbs.twimg.com/media/ETJzDaiXYAAs-v_.jpg)