Live Science reports:

People infected with the delta variant of the novel coronavirus may be carrying more than a thousand times more virus particles and may test positive two days earlier than those infected with the original SARS-CoV-2, according to an early new study. The study has not been peer reviewed and looked at only a small number of cases in China, but if the results can be confirmed, they may explain, at least in part, why the delta variant is so much more infectious.

The delta variant has now spread to more than 100 countries and currently makes up 83% of new COVID-19 cases in the U.S., with particularly high case numbers in areas with low vaccination rates, Live Science previously reported. This variant is thought to be 60% more transmissible than the previous dominant strain, and twice as infectious as the original strain of SARS-CoV-2.

Though it’s clear that delta is very good at spreading quickly, researchers aren’t sure why. To understand more, a group of researchers in China studied how the delta variant spread from the first known local transmission identified on May 21. The authors published their findings as a preprint study on Virological on July 7. [Continue reading…]