SW.2 Leads COVID Variant Mix in Late August; Test Positivity Remains Low

As of late August 2026, the SW.2 variant accounted for 21% of COVID-19 cases nationwide, followed by XFG.1.1 at 16% and RW.1.1 at 9%. The CDC reported a 4.6% test positivity rate for the week ending August 22, with COVID-19 making up just 0.5% of emergency department visits.