Herd Immunity: What Is It And How Do We Reach It? | KUNR

Herd Immunity: What Is It And How Do We Reach It?

Jan 15, 2021

Health officials say that a majority of Nevadans would need the COVID-19 vaccine for the population to receive herd immunity. That’s when enough people are immunized to slow the spread of infection. KUNR’s Lucia Starbuck has this explainer.


Lucia Starbuck: With us is Brian Labus, an epidemiologist and he’s also with Nevada’s COVID-19 medical advisory team. So Brian, what percentage of the population needs to be vaccinated in order to achieve herd immunity?

Labus: In general, we need about 70% of our population vaccinated in order to achieve herd immunity. That’s where we have a level of protection in the population that really stops disease from spreading. I think people have this misunderstanding that once we reach herd immunity, all disease goes away. Really, what it does is, it protects the population from outbreaks. There will still be cases. It’ll still be introduced. People will still get sick, it just won’t be able to explode into a pandemic.

Starbuck: How can a state, with a mix of counties and cities, achieve herd immunity?

Labus: When we talk about populations, that’s the other challenge. Do we talk about it at the county level, the city level, your neighborhood, your group of friends? Say you had a county in Nevada that had 80% of people vaccinated, but the 20% who aren’t vaccinated are all friends and hang out together, they’re going to be at very high risk and you’re going to have problems within that group, even though the larger group is generally protected.

Starbuck: What happens when we get to that part?

Labus: This is the challenge we face all the time with immunization. There are different places in the country where they have very low immunization rates, in one town or one school district, because people there all have the same opinions of vaccines and the same beliefs, and they don’t get vaccinated. Even though the state may have a 95% vaccination rate, you’re going to have little pockets where things could flare up — and that is a major challenge. This has been an ongoing challenge with vaccines in general, and it’s one we haven’t solved yet.

Brian Labus is an epidemiologist with Nevada’s COVID-19 medical advisory team.

Lucia Starbuck is a corps member with Report for America, an initiative of the Ground Truth Project.

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KUNR's Jayden Perez adapted this story for web.