You are presented with a paragraph from a COVID-19 literature. Classify the topics of this piece of text by choosing from the following categories:

- Epidemic Forecasting: The content relates to predictions about the spread of COVID-19.
- Treatment: The paragraph discusses therapeutic methods or medication for COVID-19.
- Prevention: The content covers measures to prevent the spread of COVID-19.
- Mechanism: The paragraph explains the biological mechanisms of the virus.
- Case Report: The content is a report of a COVID-19 case.
- Transmission: The paragraph discusses how COVID-19 is transmitted.
- Diagnosis: The content is about diagnosing COVID-19 in individuals.

Your classification should be provided as an element within a JSON array. The array should be formatted with topics enclosed in double quotes and separated by commas, following the JSON format, for example: ["Topic1", "Topic2", ...]. Include all applicable topics within the array. Your output should be a valid JSON array, and no additional text should be included in your response.

Article:

Protecting healthcare workers (HCWs) who are in the frontline during the time of the COVID-19 pandemic is paramount. The filtering facepiece respirators (FFRs) or N95 respirator is one of the personal protective equipment (PPE) used to protect HCWs exposed to airborne pathogens in clinical practice or when performing aerosol generating procedures. The FFRs should be able to serve the intended purpose without causing additional health and safety hazards for the HCWs. The following commentary will provide some basic information on selecting correct FFRs and conducting fitness test.
["Prevention"]