Most of us first heard the term “herd immunity” during COVID, but the concept of immunizing the population to minimize the threat of a major outbreak is far from new. 

For JP Vilai, Roseman University Pediatrics clerkship director and assistant professor, it’s paramount to curbing potential future public health issues associated with the reemergence of measles—a disease that was declared eliminated by the Centers for Disease Control and Prevention in 2000.

A quarter-century later, the U.S. is facing a new wave of measles that began when a pair of unvaccinated Texas adults were diagnosed in January. According to the CDC, it’s now spread to at least 1,227 individuals across 36 states as of June 24. Though Nevada has so far avoided joining that list, experts like Vilai cite concerns over the rising number of parents who have claimed religious and medical exemptions to opt out of state-mandated childhood immunizations.

According to a Kaiser Family Foundation report that sourced CDC data, the number of Nevada kindergartners who received both doses of the required measles, mumps, and rubella (MMR) vaccine dropped from 95.4% in the 2019-2020 academic year to 91.9% in 2023-2024. In that same span, the rate of students who claimed religious or medical exemptions increased from 4% to 7.1%. Nevada’s 2023-2024 nonmedical kindergarten exemption rate of 6.2% was the seventh highest in the nation. 

“The number of exemptions has definitely gone up. I think that COVID kind of brought that on, partially. And a more centralized questioning of vaccines coming from government agencies makes it really difficult, too,” Vilai says. 

According to a presentation given by Southern Nevada Health District representatives, the percentage of Clark County kindergartners who have received both doses of the MMR vaccine has decreased by roughly a percent annually since the 2022-2023 academic year—from 92.7% to 90.8% in 2024-2025.

According to the state Department of Health and Human Services (DHHS), Clark County’s total vaccination rate for all required vaccines fell from 92.8% in 2022-2023 to 91.4% in 2023-2024.

Ahead of next school year, the health district is doing its part to boost these numbers by hosting a series of clinics sponsored through the federally funded Vaccines for Children Program. At UNLV, another grant-funded program called Vax Facts Nevada is also working to help fill the gaps.

“Historically, Nevada has struggled with immunizations,” says Vax Facts Nevada representative and UNLV professor Brian Labus. “The goal of the project is to basically keep us from being on the bottom of the list when it comes to childhood immunization.”

Both Vilai and Labus say the rising exemption rates represent a new threat to this goal. Now that rates have exceeded 5% in Nevada, it’s more difficult to reach the 95% threshold required for the MMR vaccine to reach herd immunity.

“Unfortunately, it’s not very difficult to get an exemption. It’s much easier now for people to go to certain providers, get a piece of paper signed and turn that into the school. Sometimes it’s not a pediatrician who’s doing that,” Vilai says.

He touches on a confluence of events that led to the current moment. It starts with the pandemic, which lifted anti-vax sentiments into the mainstream. That flame was fanned even further when prominent vaccine skeptics like U.S. Health Secretary Robert F. Kennedy Jr. started publicly promoting a now-retracted study that linked the MMR vaccine to autism, he says.

“There have been many, many, many studies that have come out after that to discredit that idea, but the damage was done. It’s kind of hard to sway public opinion when it’s already out there,” Vilai says.

Kennedy has continued to promote vaccine skepticism. On June 9, he fired all 17 members of the CDC’s advisory committee on immunization, later replacing them with members who are more sympathetic to his beliefs. 

“A lot of it is about optics. If they are getting rid of the people who are experts in this field and bringing in skeptics, that sends a message to people,” Vilai says. “If the government is endorsing vaccine skepticism, it makes it difficult for your average person to go along with the opposite.”

Some Nevada parents seem to have already bought in. According to Nevada DHHS, the percentage of Nevada children who have received all recommended immunizations by 35 months old fell from 73.3% in 2022 to 64% in 2023. 

As Vilai, Labus, the health district and other groups in Southern Nevada work to flatten that curve, Vilai notes that there’s “always going to be some subset of families who are dead set against vaccines.”

Instead of focusing on them, he says the key is to convince “the fence sitters.”

“They’re not necessarily against vaccines, but not necessarily totally convinced, either. Those are the ones that I really focus the most on to convince them that this is actually very important,” Vilai says. 

But with all that’s happened since COVID—including a Trump administration that seems committed to scaling back public vaccination efforts that have become a common practice since Massachusetts vaccinated against smallpox in 1855—the road ahead may be difficult.

“It’s probably going to take a while, and I don’t know if we’ll ever really quite get back to the normalcy we saw before COVID,” Vilai says, adding that vaccination affects not only the person who’s vaccinated, but public health as a whole.

“Most parents tend to think vaccines are going to protect their own child, but there’s more to it than that. You’re protecting other people who have a deficiency or chronic health issues and can’t get vaccines. When you fall below a certain level, that puts everybody at risk,” Vilai says. “With vaccination rates kind of going down—not only in Nevada, but across the country—I think we have to be vigilant.”

Health district urges early immunizations ahead of new school year 

The Southern Nevada Health District’s campaign to help vaccinate students is an annual summer tradition. By state law, kindergartners, seventh graders and 12th graders are required to progress through a series of seven vaccines for diseases like measles, chickenpox and hepatitis. (More information on required vaccinations is available at ccsd.net/parents/enrollment.) 

Ahead of CCSD’s first day of school on August 11, the department is hosting ongoing clinics by appointment only at its main location on Decatur Boulevard and Public Health Centers in East Las Vegas, Henderson and Mesquite. An additional clinic for students 11-18 years old will be available at the Fremont Public Health Center in the two weeks leading up to the new school year. 

Senior nurse with the health district Alondra Contreras-Araiza says it’s important for parents to remember to first submit their child’s previous immunization record to the district, adding that her team can help new Nevada residents transcribe existing out-of-state records.

Contreras-Araiza urges parents to schedule appointments as soon as possible and notes that students can also get their vaccines up to one year before they’re required—meaning a child can get their kindergarten shots after they turn four. 

“Everyone wants their shot the week before school, but it’s honestly physically impossible to vaccinate the whole Valley if we all wait until the last minute,” she says. 

To schedule an appointment, visit snhd.info/bts or call 702-759-0850.

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