National index evaluates how COVID vaccines impact an area's risk for virus

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BySamantha Kummerer WTVD logo
Tuesday, June 22, 2021
How do vaccines impact an area's risk for COVID-19?
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An NC State professor is leading the team behind the Pandemic Vulnerability Index, which evaluates how vulnerable a community is to COVID-19.

As vaccination rates across the country plateau, experts hope to better understand how vaccines impact a community's risk for COVID-19.

The National Institute of Environmental Sciences recently updated its Pandemic Vulnerability Index to include vaccination rates for counties across the United States.

Previously, the index factored in things like an area's population density, demographics, insurance rates and mitigation efforts to evaluate how vulnerable it was for COVID-19.

Dr. David Reif is leading the team behind the PVI and is a professor at North Carolina State University.

"There are a lot of social justice, environmental justice, health disparity issues that go into vaccination rates and vaccine hesitancy...there are lots of things that go into that, and the new model reflects that," Reif said

Dr. Reif explained how the update will give officials a better real-time look at risk while helping officials better predict how the virus might impact counties going forward.

"So, we said vulnerability includes more than just how many people are hospitalized or how many people are dying, it's many factors," Reif said. "Adding in the vaccines makes a big improvement to how well we can predict what's going to happen over the next 30 days in a given county."


Robeson County has one of the highest rates of overall COVID-19 cases per population. This level of risk is predicted under the PVI, which ranks the county as one of the most vulnerable in the state. Despite the elevated risk, the county also reports one of the lowest vaccination rates in the state.

"It is frustrating," said Raymond Henley, the director of physician service UNC Southeastern Health, "We try to understand exactly where their patients are coming from. We are seeing some improvement in our hospitalizations, we're seeing an improvement in positive testing, and we know that in some ways, that's positive news, but it's also presenting a barrier because we're trying to educate the community that, 'Hey, COVID is still here.'"

For Henley, all the factors included in the PVI model are interconnected and also impact people's decision to get vaccinated.

"I think that when you combine that with other comorbidities of transportation and social determinants, unemployment rates, I think all that sets up a stage where of information and education is not getting to the patients in the way that they understand; the way that they can make an informed decision," Henley said.

A previous I-Team analysis found the North Carolina counties with the highest overall risk of contracting COVID-19 also vaccinated on average 6% fewer residents then the counties with the least risk.

With the new PVI model that factors in vaccination rates, Robeson County's overall vulnerability decreased slightly.

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The I-Team found about 40% of North Carolina counties reported reduced risk when factoring in vaccination rates. Many of the counties the PVI predict are less vulnerable now were previously reporting the highest level of risk.

Reif also hopes the updated PVI will be able to help show unvaccinated people the broader impacts of receiving a dose.

The PVI shows changes in a county's predicted vulnerability over time and for many areas in the state that level has decreased since vaccination efforts began in early 2021.

"If a lot of individuals take steps towards safety, the whole community improves right? And that's really what we're going for is that idea of vulnerability is about where you are and who your neighbors are and how your communities work," Reif said.

While counties are constantly looking at targeted data like the PVI model, Henley said there's no magic solution.

"We're really having to engage patients in ways that we really haven't done so before; getting them to trust the process, getting them to put their trust in us and so I think that in itself is unique, and nobody can really foretell or really kind of forecast exactly," Henley said.