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San Diego’s Collective Immunity Threatened By Declining Vaccination Rates

Daniela Mejia, a mother, is shown explaining why her daughter is one of thousands of young children in San Diego County who aren’t up-to-date on their vaccinations.
Katie Schoolov
Daniela Mejia, a mother, is shown explaining why her daughter is one of thousands of young children in San Diego County who aren’t up-to-date on their vaccinations.
San Diego’s Collective Immunity Threatened By Declining Vaccination Rates
San Diego’s Collective Immunity Threatened By Declining Vaccination Rates
When Daniela Mejia’s daughter Julieta was born, the first-time mother was wary of vaccines.
San Diego’s Collective Immunity Threatened By Declining Vaccination Rates
San Diego’s Collective Immunity Threatened By Declining Vaccination Rates GUESTS:Joe Yeradi, reporter, iNewsourceDr. Ellen Rodarte, Sharp Rees-Stealy Medical Centers

As of today the measles count in California is up to 79 confirmed cases. Most stemming from an outbreak at Disneyland in December. This recent group of infections is gained national attention and put a spotlight on the relatively high rates of on vaccinated children in California. J bps news partner I do source those with the numbers to find out how many children entering school in San Diego County without being vaccinated that is for illnesses such as measles, whooping cough and polio. Joining the art Joey rotted with our new source and Joe welcome to the show I Maureen And Dr. Alan Rodarte who practices family medicine at Sharp Rees Steely medical center. Joining the art Joey rotted with our new source and Joe welcome to the show I Maureen And Dr. Alan Rodarte who practices family medicine at Sharp Rees Steely Medical Ctr., Dr. would've taped it defer commitment Thank you boring Not sure you compile stated on the number of unvaccinated kindergarten age kids in San Diego. What defined? What we found that among all kindergartners in the 2014 to 2013 school year this is both public and private kindergartners -- we had about 7.6% of students who were not fully up to date on their immunizations. That's down from about 9 1/2% last year but it's up from under 6% at the data go back when you say not fully immunized, some have had some shots and some have had nine is right? Is right. There's a portion of them were just behind on some shots and whose parents say that they'll get them up today quickly. They're loaded conditionally. There are also some hundred orders can't be vaccinated medically because their immune systems are too weak and there are some kindergartners whose parents have a personal belief exemption where they don't want to vaccinate their children. Is legally allowed here in California. And the numbers on those personal belief exemptions have been going up in recent years concerning a large number of the medical community. Now would schools in the county have the highest number of unvaccinated kids just started school? It was interesting. I took a look at private versus public and also just among public schools with higher proportions of students who qualify for free or reduced meals and what we found is that the number of kindergartners who have these personal belief exemptions at private schools was considerably higher than at public schools and among public schools at those schools where fewer kids qualified for this free or reduced meal benefit the number is also quite a bit higher than at the schools where more students were poor enough to qualify for the benefit. So it seems that better educated and wealthier parents for whatever reason are the ones who are opting out of vaccinating their children. Now Dr. Rodarte it the I new source investigation did find a decrease from last year and the number of unvaccinated kids entering school. But is the rate still alarm into the medical community? Well I review the wonderful map and it is concerning because what happens is some schools -- 97% are immunized -- but some of the schools have immunization rates that are very low and put everyone at that school at risk. But you don't need any that many of the newest children in the group asked to do -- would get passed for 5% of on immunized children you're getting this -- Some parents might think you know if most kids are vaccinated and some parents choose not to vaccinate their children come up that they're really just putting their own child at risk of may be coming down with an illness. But there are larger concerns right I mean -- how does that actually work? So the immunizations are incredibly incredibly say. Some folks say well I'm not going to put my child it was for immunization to protect someone else -- but there is minimal risk with immunization. These immunizations are a miracle and any side effect we see is a low-grade fever which is actually a sign that the child's immune system is responding to the wonderful immunization. And if you children are not immunized, they actually put at risk of kids who cannot be immunized right Yes oh children under 12 months can't be immunized for measles so right now I have many young families coming in with their instant saying would why do to protect my two-month-old probe measles -- they can't they don't even have the choice. When a family makes a choice not to immunize their child, -- with the MMR in a year they're putting all these babies at risk Now Joey spoke with a woman Donya LeMay half from Imperial Beach, she doesn't plan on vaccinated before-year-old. What reasons does she give for that? Well she was concerned about potential side effects from the vaccine. She didn't want to she said exposer child to all of these pathogens all at once through vaccine in rather want her to gradually and naturally come into contact and allow her immune system to strengthen the naturally. And do think that's a valid concern Dr. Rodong take I tell folks that the immunizations are one of the most natural and effective interventions we have. So we give children a tiny dose of an antigen in their body naturally makes us wonderful response -- if you don't immunize your child, then the other response that if they come in contact with the city they call that natural but actually can cause a lot of bad side effects And I believe that when the spoke with Daniela, she was concerned about her child contracted one of these contagious illnesses which she was that explain she was in concerned about one of her children contracting these illnesses and infecting another tell because there's other ways to strengthen the immune system. I have respect for vaccinations and I know they're there when they choose them or if I choose them -- but I also know that there's other options. There's other options just to strengthening the immune system and defending ourselves against these things and I make it that's -- -- by choice -- simply as a parent -- is that to explore our options. Joe did she go into any detail about what those options by the? Yeah Daniela is a holistic healer. She's also a massage therapist. Shibley sorry much in Chinese medicine and homeopathic medicine and holistic healing and so she was pretty confident that she could take care of her daughter using those natural remedies. What would you say to this woman Dr. Rodarte it if she were your patient? I would talk to her about her fears with the immunizations. What we want to do is make sure that these parents know that we care about the health of their children as much as they do in the yes attention work together. But the best way to protect her child from these terrible diseases is through immunization. Is this are you thinking that perhaps this news. Break me actually prompt some people to reconsider their can decision not to immunize their children considering how this disease is spreading? I hope so. I hope so because this is just measles but every child was not immunized for measles is also at risk for rubella comedy congenital rubella is a terrible disease and I hope this makes people remember that these are real diseases. All of them and that their diseases that all they haven't seen them along talk about we in medicine see them and we know them and we care for families with hepatitis B with congenital rubella and we just want to protect their children and their families from these diseases. As you're crunching these numbers Joe, was anything surprising to you? I think the thing that surprised me the most really was the fact that it seem like the students at private schools and the students that the highest performing wealthiest public kindergartens were the ones who did have these highest rates of personal belief exemptions because you would think that well if these parents are wealthy though are probably the better educated and that kind of threw me for a loop by the doctor who I interviewed for the story said look -- you know just because you have a college degree just because you happen to be highly educated doesn't necessarily mean that your highly educated and immunology. Or that you necessarily understand cause-and-effect so well so -- you know -- it could very well be that perhaps there's not really much relationship to level of education and perhaps understanding of how these vaccines work Or perhaps you think you know. If you're smart another other subject you think you can understand what's going on when you don't have the basic medical knowledge really sort of to make a wise decision. Yeah those of us in medicine when we look at the science come up there's no question in our minds these are effective and safe. Right now the full course of immunizations we give children is 1/10 the amount of damage and that the kids got in the 1980s. So we know that we have a long history of these children getting these immunizations we know they're safe -- we just want to address the fears and make sure that these parents that are opting out we include them and talk to them as a community and decide -- open decide to do the best thing. And for people who are interested, they can go to see this I do source interactive vaccine map to see which schools have the highest number of unvaccinated kids and so forth all throughout San Diego County. You can go to I've been speaking with Joe you're already with dinosaurs and Dr. Elinor Duarte was sharp Seeley medical centers thank you both Always a pleasure Thank you Maureen.


When Daniela Mejia’s daughter, Julieta, was born, the first-time mother was wary of vaccines.

"I wouldn't want to have my daughter suffer from any side effects of such a sudden invasion of infectious disease that was just given to her, you know?,” Mejia said. “I'd like her to be exposed slowly to bacterias and viruses and just naturally."

Because of her mother’s concerns, Julieta, now almost four, is one of thousands of young children in San Diego County who aren’t up to date on their vaccinations.

More than 3,300 kindergarteners -- in both public and private schools -- began the 2014-15 school year lacking one or more recommended vaccinations against diseases such as measles, polio and whooping cough, according to an inewsource analysis of data from the California Department of Public Health and the California Department of Education.

That’s nearly 8 percent of the county’s kindergarten population.


Interactive: Map Of Kindergarten Vaccination Rates In San Diego County

And while that represents a decline from the 2013-14 school year’s rate of almost 10 percent, it’s still an increase from a decade ago when the rate was less than six percent.

Immunologists are raising the alarm about what they say is our collective amnesia over the damage these diseases have wrought in the past.

Dr. Shane Crotty, a professor at the La Jolla Institute for Allergy and Immunology, said a parent’s decision to vaccinate their child is motivated by fear.

“It really comes down to two fears,” he said, “the fear of something happening if you get vaccinated versus the fear of something happening if you don’t get vaccinated.”

As decades of widespread vaccination eliminated once-feared diseases from the collective conscience of American parents, the first fear took preeminence in the minds of some.

“You’re like ‘Well, yeah, OK. I won’t vaccinate because I have this small little fear [of vaccination complications] because on the other side you really have no fear of your kid getting measles or polio because you’ve never seen it,” Crotty said.

Mejia believes that vaccines do work and could be right for some children. But the holistic care practitioner and massage therapist said that once she researched their potential dangers, she decided the risks were too great.

“This is research that one has to do on their own, like 'What are my options?' instead of out of fear, doing what my doctor said,” Mejia said.

That fear of vaccines’ complications (greatly overwrought, say scientists and medical professionals) -- and the decisions it leads to -- threatens not just the children whose parents choose not to vaccinate, but other children as well.

Thinning The Herd

So called “herd immunity” is the theory that at some point, enough members of a given population or “herd” are vaccinated against a particular disease that even the unvaccinated are protected.

The precise level at which a group achieves herd immunity varies by disease. For polio, the number usually given is around 85 percent. For whooping cough (also known as pertussis), many doctors say 92 percent or higher is required.

Herds can be any group in which members come into physical contact with each other, from a kindergarten class to an entire county.

Dr. James Cherry, a pediatric infectious disease specialist at the UCLA Medical Center, said maintaining herd immunity is crucial for a community’s well-being.

Cherry used measles as an example. A current outbreak of that highly contagious disease is believed to have originated with a visitor to Disneyland who was not vaccinated. Cherry said measles requires a 95 percent immunization rate to maintain herd immunity.

“When the overall herd immunity drops below that number and down to something like 90 percent, then you’re in trouble because then you’re going to get sustained transmission,” Cherry said.

Database: Kindergartens' Vaccination Exemption Rates

Mejia doesn’t believe that her decision not to vaccinate her daughter can affect the well-being of children who are vaccinated.

“If they have the vaccine, doesn’t that mean that they will be able to fight it off?” Mejia asked.

Crotty said that’s a common belief among parents. It’s also wrong.

“If there are unvaccinated kids who are getting sick, that absolutely raises the risk of vaccinated people getting sick because the vaccines aren’t perfect,” Crotty said.

Many vaccines work perhaps 95 percent of the time, Crotty said.

And not every child can be vaccinated before they’re exposed to unvaccinated children.

As an example, Crotty points to whooping cough. Children can’t be fully vaccinated against whooping cough until they’re more than a year old. Those babies’ vulnerability increases when they come into contact with unvaccinated older children.

“Whooping cough kills babies,” Crotty said. “And you can’t vaccinate the babies.”

They rely on herd immunity.

“The way to protect babies under 12 months is to have everybody else vaccinated so you get the herd immunity,” Crotty said.

The same goes for children with autoimmune disorders who can’t get vaccinated no matter their parents’ preferences.

Personal Beliefs

The data of vaccination records for kindergarteners shows that personal belief exemptions -- the opt-out parents can sign against immunizing their school children -- tend to be utilized by higher-income and presumptively better-educated parents.

A recent study found that as the percentage of people with graduate degrees in a neighborhood increased, so too did that neighborhood’s percentage of under-vaccinated children.

This phenomenon seems to hold in San Diego County, where nearly half of all non up-to-date kindergarteners had a personal belief exemption.

In the 2014-15 school year, the personal belief exemption rate among kindergarteners attending public school was 3.3 percent. The rate among kindergarteners attending private school was 5.8 percent.

The difference was even more pronounced when comparing the socioeconomic profiles of public kindergartens.

Among kindergarteners attending public schools where more than half of the student population qualified for free or reduced-cost meals, the personal belief exemption rate was 1.6 percent. The rate among kindergarteners attending public schools, where half or less of the student population qualified for the benefit, was 5.5 percent.

Cherry, the UCLA infectious disease specialist, wasn’t surprised by inewsource’s findings.

“The whole middle aisles of Whole Foods Markets are selling crap,” Cherry said. “And these are the people who go there.”

Cherry noted that Hispanics, whose educational attainment has historically trailed that of white Americans, have the highest proportion of vaccinations against whooping cough of any major ethnic or racial group.

“Because you have a college degree doesn’t mean you understood epidemiology or you understood cause and effect,” Cherry said.

Mejia currently takes Julieta to daycare a couple times a month. She hopes to enroll her in pre-kindergarten next month.

It’s a “co-op” school where Mejia estimates up-to-date vaccination rates may be as low as 80 percent.

Said Mejia, “So, this is actually a school where more parents share my point of view.”

inewsource investigative assistant Madison Hopkins contributed to this report.

Corrected: May 28, 2023 at 6:42 AM PDT
KPBS' Patty Lane, Peggy Pico and Maureen Cavanaugh contributed to the Midday and Evening Edition segments.