Antigen tests: What are they and do they work?

The European Commission has a  document on its website which lists antigen tests whose results are “mutually recognised”

Also referred to as rapid self-tests, antigen tests do not require a laboratory to process the sample and issue results in a short period of time, usually under 30 minutes. Photo: Gareth Chaney/Collins

Also referred to as rapid self-tests, antigen tests do not require a laboratory to process the sample and issue results in a short period of time, usually under 30 minutes.

Why have they been in the news in recent days?