How Do COVID-19, PCR and Antigen , Tests Compare?.br CBS reports that as demand for COVID-19 br tests grows, choosing and using br different types of tests can be confusing.br PCR tests are reportedly br considered to be the "gold standard" when br it comes to spotting SARS-CoV-2 infections. .br In comparison, antigen tests, otherwise known br as lateral flow tests, are reportedly less br sensitive than their PCR counterparts. .br However, antigen tests are a popular br alternative, as they can be taken at homebr and return quicker results. .br According to CBS News, antigen tests work br best in symptomatic people within br the first week of infection. .br Last year, one review estimated that br antigen tests may only spot about 75 br of cases that a PCR test would detect. .br PCR tests are still by far the best test br and those are the tests that most hospitals br are using to identify COVID-19 patients, Dr. Emily Volk, president of the College br of American Pathologists, via 'CBS Mornings'.br PCR tests are still by far the best test br and those are the tests that most hospitals br are using to identify COVID-19 patients, Dr. Emily Volk, president of the College br of American Pathologists, via 'CBS Mornings'.br Currently, antigen tests remain in short br supply and can be difficult to find at br many stores or online retailers. .br CBS reports that starting this month, br the White House plans to offer a website br that will distribute free at-home tests. .br The plan reportedly will require health insurers to reimburse the cost of purchasing at-home tests. .br The appropriate tool in this pandemic br to answer the question, 'Do I need to isolate? br Am I infectious and a risk to my neighbors?' br is using a rapid antigen test because it only br stays positive as long as you are infectious, Dr.