Medical experts explain why herd immunity is becoming more difficult to achieve

Updated: May. 13, 2021 at 9:41 PM CDT
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AMARILLO, Texas (KFDA) - In a nut shell, herd immunity is when enough people have antibodies or immunity that a virus can be controlled or no longer spreads.

However, doctors say not enough people are getting the vaccine or have natural protection to achieve herd immunity with COVID-19.

According to doctors, one of the reasons is the threshold number could be higher than we thought.

To better understand why thresholds change, I spoke with a epidemiologist with the Texas Tech Vet School about how this has worked with animals, given that is where the term began.

“It is what we call the degree of contagiousness on transferability of a specific pathogen. So, that basic reproduction number defines the term used to determine how contagious the pathogen is and will determine the kind of herd immunity or kind of threshold needed to achieve,” said Dr. Babafela Awosile, PhD, assistant professor of Epidemiology at the Texas Tech University, School of Veterinary Medicine.

For COVID-19, the growing variants have made it more contagious and caused the threshold to increase.

“We have a lot of scientists who are working to determine what is the optimal level of herd immunity and I think some of that is still going on. And yes, we read in the literature that 70 percent but I think that the actual number or the final number is still in progress,” said Dr. Saroj Rai, PhD, scientific advisor for the Texas Department of State Health Services.

Here, Potter County has 29 percent of its eligible population fully vaccinated while Randall County has 34 percent fully vaccinated.

This is not counting those who have natural immunity from recovering from COVID-19.

Still, many doctors believe the actual number to contain COVID-19 now is actually closer to 90 or 95 percent.

But, doctors note it depends on the population density, virus contagiousness and movement.

So, herd immunity here is different to herd immunity in other areas.

“Even though we don’t achieve herd immunity and have this thing go away for good, that doesn’t mean that our window of opportunity to do the right thing is lost,” said Dr. Rodney Young M.D.,regional chair and professor of Family and Community Medicine at Texas Tech University Health Sciences Center School of Medicine. “We can greatly improve the future prospects of the disease burden that we will all have to live with related to COVID through a broad scale adoption of the vaccine efforts.”

He adds this just means that like the flu, scientist will continue making vaccines that we would routinely get to protect from the developing variants.

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