Concerns are heightened across the United States as the East Coast experiences an unexpected outbreak of measles.
A CBS News investigation revealedare at risk of similar outbreaks as vaccination rates drop below the Centers for Disease Control and Prevention's recommended 95% for student bodies, hundreds of which are located in California.
While it's up to the parents to immunize their child based on medical recommendations, schools across the country are required to keep track of student's immunization records, including the Golden State.
As many as 350 Southern California schools that do not meet the recommended threshold to prevent the unwanted return of measles based on the investigation, troubling numbers that are at the top of mind of many local medical professionals.
Dr. Steven Nishibayashi, a former pediatrician, recalls his own battle with the illness when he was just five years old.
"It's one of my earliest memories," he said. "The fever and the cough and the itchy rash. ... I vividly recall the night that my fever was high, the spiders were attacking me, and it was as real as I remember it to be."
Now, more than 60 years later, the memories still linger, even though he knows it was just a hallucination.
"At the moment it was very, very scary and frightening."
He used the terrifying experience to motivate his professional passion, turning his career goals towards medicine.
"It was a constant reminder of my motivation to become a pediatrician," he said. "To prevent preventable illnesses."
Over the course of his career, Nishibayashi expects that he saved thousands of children from suffering with measles, which can sometimes turn fatal.
A new vaccine was supposed to make measles completely preventable by 1963, leaving the illness in the past. However, what were once absolutes on the truth behind vaccinations have turned into doubts.
A series of sudden outbreaks have led measles to find its way back into headlines,.
Nishibayashi says that each of the positive cases in Philadelhpia occurred in unvaccinated people. He says that California is not exempt from suffering a similar fate.
In California, the state tracks vaccinations, requiring them for students before they start kindergarten. Schools themselves must also keep records by law.
However, the California Department of Public Health is now auditing 450 schools for not meeting the 90% threshold of fully-vaccinated students, 195 of which are specifically for measles, a tenth of which sit under 75%.
Two of those schools have a 0% vaccination rate, while another sits at just 9%.
"It could spread really quickly if we don't have herd immunity," says Nava Yeganeh with the Los Angeles County Health Department.
She says that 95% of students have to be vaccinated in order to reach herd immunity that would prevent a large outbreak, and that numbers below that line is dangerous.
Hundreds of Southern California schools below threshold
Of those schools currently below the recommended level, 50 are located in Orange County, 41 in San Bernardino County, 32 in Riverside County and 18 in Ventura County.
Data shows that 209 schools in Los Angeles County are below herd immunity, 61 of which are within the jurisdiction of Los Angeles Unified School District.
"There's again these pockets we're seeing where the rates are lower," Yeganeh said. "We've identified them and mapped them out."
The Department of Health's numbers are lower, even though they include day care centers in their analysis.
"We have about 80 less, are less than 90%," Yeganeh said, something that they are trying to address.
Data from Oct. 2021 to March 2022 shows that Los Angeles' Art in Action Community Charter School only had 70% of their students vaccinated.
Jamie Kikuchi, a teacher at the charter school, says that 70% is not accurate to what they report. School data shows that their current vaccination rate is currently at 98.6% a jump from the 98.4% in 2023.
"We have a very thorough student enrollment registration process," Kikuchi said. "We have all the families submit vaccination cards. ... Students are not allowed to register unless they fulfill that. So, under 70%, I'm not sure where that data is coming from. If it's coming from the state, it might be that the data is off or that there's an error in reporting."
The state later confirmed that the school reported 70% for the 2021-22 school year and the charter clarified that there were paperwork issues that prevented them from reporting anything higher at the time.
Yeganeh says that while it's law to get vaccinated in order to attend school in California, it falls on schools to track those numbers and ensure that their students stay up to date.
When asked if schools just aren't doing the job, Yeganeh said that there "may just be a lack of resources."
She did say that the health of many children is at stake.
"I definitely am worried," Yeganeh said on a potential outbreak. "I think we really need to do whatever we can."
The CDC says that death from measles is rare, with the rate sitting at one in every thousand.
LAUSD's chief medical director was unavailable to speak about the district's vaccination rates, and requests from KCAL have not yet been answered by district officials.
When contacted, schools in every county that showed low vaccination rates reported that their numbers were corrected as soon as they were notified.
Concerned parents can request vaccination numbers from their children's schools.
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