Study shows the viral loads in the Delta infections are ~1000 times higher than those in the earlier strain infections on the day when viruses are firstly detected.

Viral infection and transmission in a large well-traced outbreak caused by the Delta SARS-CoV-2 variant – Virological.org

Commentary: The Delta Variant Isn’t Just Hyper-Contagious. It Also Grows More Rapidly Inside You – NPR

Related: WHO: Delta variant is ‘most transmissible’ identified so far. AND Increased transmissibility and global spread of SARS-CoV-2 variants of concern – “Estimated transmissibility increases of alpha 29% (95% CI: 24–33), beta 25% (95% CI: 20–30), gamma 38% (95% CI: 29–48) & delta 97% (95% CI: 76–117)”.

Commentary on Twitter

Part of the challenge that Delta presents may be tied to this finding
The variant's viral load ~1,000X higher than previous strains (reflected by low CTs), more infectious in the early stages of the illnesshttps://t.co/09CDQFwCSV pic.twitter.com/mjIfcNTYlO

— Eric Topol (@EricTopol) July 9, 2021