This is supposing that it’s asked either in idle conversation with a person known to you, or the person asking you is a complete stranger to you, or your employer, or your school’s staff, or is an employee at a venue or a business that you are entering, etc. It is not meant to cover medical professionals in the performance of their duties in relation to your health care. There are various reasons the question might be asked, so it is possible that your answer here may take more elaboration than just no or yes.
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