Here’s how Delta Variant has slowed down COVID herd immunity

Published: Jul. 20, 2021 at 9:53 PM CDT
Email This Link
Share on Pinterest
Share on LinkedIn

BIRMINGHAM, Ala. (WBRC) - As COVID-19 cases rise and some health officials raise the alarm, we wanted to know...are we any closer to herd immunity? Increased cases are actually a step back, and you can blame the Delta Variant.

Herd immunity has often been misinterpreted, says Jefferson County Health official Dr. Wesley Willeford.

“It means, basically saying, there’s enough immunity, within a particular group of people that a particular disease, usually a virus, cannot spread easily,” said Willeford.

It happens when enough people have had COVID or gotten the vaccine.

The potential of spread is called “r naught.”

“It’s a term that we use in epidemiology of how many people one person can go on to effect with a particular virus or disease,” said Willeford.

Previous estimates for COVID herd immunity are no longer valid, he says.

“What’s changed recently is Delta Variant, Delta Variant has a much higher r naught value,” Willeford explained.

One person with Delta Variant can go on to infect as many as 8 people... and with that, herd immunity is even further off.

Simply put, “cases are on the rise right now, so we are not at herd immunity right now in Alabama,” said Willeford.

With low vaccination rates, the future for herd immunity is not bright.

Copyright 2021 WBRC . All rights reserved.