R0- R Nought, No. of People A Sick Person Infects On Ave: Chick Pox, 9-10, Flu, 2, Covid Delta 6-7

[appalachiablue]

The CDC Said The Delta Variant Is As Contagious As Chickenpox. That's Not Accurate, NPR, Aug. 11, 2021. - Ed.

In a leaked report, the CDC made a surprising claim about the delta variant of the coronavirus: It "is as transmissible as: - Chicken Pox," the CDC wrote in a slideshow presentation leaked to The Washington Post, 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. The number of people that one sick person will infect (on average) is called R0. Here are the maximum R0 values for a few viruses. "Yeah, I didn't find the CDC's statement entirely accurate," says Wenseleers..

Nonetheless, delta is still highly transmissible, he adds. "It's probably the most contagious respiratory virus that we know, for the moment," he says.

Here's why. When scientists measure a virus's transmissibility, they often use what's known as R0, or "R nought. " It's the number of people a sick person will infect when the entire population is vulnerable to the virus. "So it's the virus's potential of spreading, given ideal conditions for the virus, when no one has any immunity," says computational biologist Karthik Gangavarapu at the Scripps Research Institute.

For example, the flu has an R0 of about 2. Each person infected with flu passes the virus on to 2 people on average. Some people will infect more than 2 people, and some will infect fewer. But over time, the average will be about 2. Chickenpox, on the other hand, is way more contagious.. Chickenpox has an R0 of about 9 or 10. Outbreaks are explosive...."For the delta variant, the R0 is now calculated at between 6 and 7," Wenseleers says. So it's 2-3 times as contagious as the original version of SARS-CoV-2 (R0 = 2 to 3) but less contagious than the chickenpox (R0 = 9 to 10)....

More,
https://www.npr.org/sections/goatsandsoda/2021/08/11/1026190062/covid-delta-variant-transmission-cdc-chickenpox

'Contagion' movie (2011), Matt Damon. 'It's mutated, we have a new R Nought.'

[hlthe2b]

1. Yet they manage NOT to compare it to the MOST infectious virus known, measles, with R0 of 18?!

Perspective is sorely needed. Yes, Delta's increase infectivity and possible virulence is a major concern. BUT it is not the most infectious virus we've had to deal with--far from it.

That said, I absolutely agree with instituting all possible barriers to the virus from masking (higher efficacy filtration if possible, but at least well constructed/tightly fitting surgical or multiple layer cloth masks), distancing, avoiding unmasked indoor activity, ensuring as much ventilation air turnover as possible and of course vaccinations and hand-washing.

[appalachiablue]

2. Agree, that covers it. 'Measles' is rarely heard..