“A recent study has even suggested that respiratory samples from people infected with the Delta variant can harbor up to 1000 times higher viral loads compared to samples with variants that are more closely related to the original Wuhan strain, although the sample size of this study was very limited. Here, we have compared the viral load in 16,185 samples that were obtained during which non-VOC, the Alpha (B.1.1.7) or Delta variant (B.1.617.2) were dominant as evidenced by genomic surveillance. We found that the Delta variant contained about 4-fold higher viral loads compared to the non-VOC or Alpha variants.”
Here is another study on viral load:
“A recent study has even suggested that respiratory samples from people infected with the Delta variant can harbor up to 1000 times higher viral loads compared to samples with variants that are more closely related to the original Wuhan strain, although the sample size of this study was very limited. Here, we have compared the viral load in 16,185 samples that were obtained during which non-VOC, the Alpha (B.1.1.7) or Delta variant (B.1.617.2) were dominant as evidenced by genomic surveillance. We found that the Delta variant contained about 4-fold higher viral loads compared to the non-VOC or Alpha variants.”
But also see the comment there.