The Delta Variant Isn't As Contagious As Chickenpox. But It's Still Highly Contagious

The Delta Variant Isn't As Contagious As Chickenpox. But It's Still Highly Contagious A leaked CDC document compared it to the highly contagious children's disease. Data does not support this claim. Nonetheless, the variant is one of the world's most contagious respiratory diseases. NPR.org

In a leaked report, the Centers for Disease Control and Prevention made a surprising claim about the delta variant of the coronavirus: It "is as transmissible as: - Chicken Pox," the agency wrote in a slideshow presentation leaked to The Washington Post on July 26.

Chickenpox is one of the most contagious viruses known. Each individual can spread the virus to as many as "90% of the people close to that person," the CDC reports.

Is the delta variant that contagious as well?

The short answer is no, says evolutionary biologist and biostatistician Tom Wenseleers at the University of Leuven in Belgium.

"Yeah, I didn't find the CDC's statement entirely accurate," says Wenseleers, who was one of the first scientists to formally calculate the transmission advantage of the alpha and delta variants over the original versions of SARS-CoV-2.

Nonetheless, delta is still highly transmissible, he adds. It's one of the most contagious respiratory viruses that we know of, he says.

Here's why.  ...