RNA viral loads of SARS-CoV-2 Alpha and Delta variants in nasopharyngeal specimens at diagnosis stratified by age, clinical presentation and vaccination status.

•Overall, higher SARS-CoV-2 RNA loads are seen for the delta variant compared to the alpha variant within 2 days after symptoms onset.•SARS-CoV-2 RNA loads were higher for the delta than the alpha variant, in both asymptomatic adults and children.•For COVID-19 patients, SARS-CoV-2 delta RNA loads were higher in non-vaccinated individuals compared with vaccinated participants.•Asymptomatic vaccinated and unvaccinated individuals displayed similar SARS-CoV-2 delta RNA loads.