Diagnostic tool or screening programme? Asymptomatic testing for SARS-CoV-2 needs clear goals and protocols

Countries’ increases in testing capacity during the first waves of the COVID-19 pandemic, coupled with reductions in case numbers between waves, have resulted in shifts from diagnostic testing of symptomatic patients to mass screening. Viewed from the perspective of United Kingdom testing, it is therefore arguable that the largest asymptomatic testing programme, by testing rate, ever attempted in the country is currently being deployed. Other countries are deploying similar programmes. Even with the advent of further waves of infection, especially associated with northern hemisphere winter, asymptomatic testing is still occurring, and it can be anticipated that as waves recede and seasons change it will again increase.