This study, led by researchers from the Centers for Disease Control and Prevention (CDC), finds that symptomatic individuals with an initial negative home antigen test should test again 1 to 2 days later because test sensitivity peaks several days after COVID-19 onset.
In 225 adults and children with confirmed COVID-19 infection, antigen test sensitivity was 64% compared with same-day RT-PCR testing and 84% compared with same-day viral cultures.
Antigen test sensitivity peaked 4 days after illness onset at 77%, and sensitivity improved with a second test 1 to 2 days later at 81% to 85%. Six days after illness onset, antigen test positivity was 61%.
The results suggest that sensitivity of home antigen tests for COVID-19 was moderate compared with RT-PCR and high compared with viral cultures. The results also suggest that antigen test sensitivity peaked several days after illness onset and improved with repeated testing, the researchers say.Read More >>