Measles, a disease once declared eradicated in the United States, has swept into almost 30 states since last year.
Could South Florida be next? Experts say “maybe.”
More Miami-Dade kindergarteners, about 2,500 last year, enter school without their shots than in any other Florida county. The result is an overall vaccination rate on the low end of what public health experts call the “herd immunity” range needed to prevent outbreaks. Elevating the risk factor: Rates at dozens of individual schools across the county fall far short of the target.
“We’d like to see Miami-Dade get higher,’ said Dr. Judy Schaechter, who chairs the county’s immunization coalition. “We have more challenges ... but we want to make sure we get on top of that.”
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Florida Department of Health data show the county’s biggest challenge may be the large number of immigrant children who move in and out of schools throughout the year, often arriving from poor countries with marginal health care. Many are admitted under “temporary” exemptions allowed by the state, which indicate they have started but not yet fully completed immunization programs.
A smaller but more controversial contributor: Parents are increasingly foregoing vaccinations. Over the last decade, state records show, there’s been a slow but steady rise of Miami-Dade parents claiming a “religious” exemption, reaching 1 percent in the last school year. It’s a trend mirrored across Florida and the country, with a small but adamant group of parents arguing against mountains of science for a “right” not to vaccinate.
Dense communities and a large and steady influx of tourists only add to South Florida’s potential vulnerability, public health experts say.
In Miami-Dade, the state says, 92 percent of kindergarteners were fully immunized in 2013, the most recent year of data available. That’s close to the state’s health department goal of 95 percent but still places the county in the bottom 10 in Florida, according to health department data.
Eben Kenah, an assistant professor of biostatistics at the University of Florida, said Miami-Dade’s overall rate is “probably too low” to provide widespread protection. And the rate also masks what he said may be the most serious vulnerability to the potential spread of measles — schools where rates fall far below average.
“It’s like a dry spot in the forest,” Kenah said. “Maybe it will be OK, but if it gets hit by lightning, it will burn.”
Records from the Miami-Dade school district show a number of schools fall into that category. About 40 fell below a 75 percent vaccination rate this year. Among the lowest: Allapattah Middle, Carol City Middle and Andover Middle in Miami Gardens. At 63 percent, Lawton Chiles Middle just west of Miami Lakes had the lowest rate.
The district points out that those schools all have very high rates of “temporary” exemptions.
David Moore, a district assistant superintendent, said the large number falling into that category “basically speaks to the transient population of Miami-Dade.”
Since last year, measles has infected only 765 people nationally. But the speed and extent of the spread have alarmed many health officials and increased calls to raise vaccination rates across the country.
In Florida, records show, only about half of the counties meet the goal set by the state health department for vaccinations of kindergarteners. And it’s not totally certain that number is enough to prevent an outbreak, with some experts giving varying and higher figures to assure “herd immunity.”
Herd immunity is important because some people simply can’t get vaccinated, including babies or people with weakened immune systems — like cancer patients.
“We need to protect those people, too,” said Schaechter, who is also chief of the pediatric department at the University of Miami, and chief of service at Jackson Health System’s Holtz Children’s Hospital. “In this one, we are our brother’s keeper.”
But the percentage of Miami-Dade kindergartners skipping their shots has risen, reflecting a trend of parents questioning their safety or motives of pharmaceutical companies. With the spread of measles, the opt-out issue has sparked national controversy, with a few politicians — notably Republican presidential prospects Sen. Rand Paul and New Jersey Gov. Chris Christie — advocating for parental “choice” before backing off after widespread backlash. Another likely GOP contender, Florida Sen. Marco Rubio, has said “absolutely” all children should be vaccinated.
Most medical professionals urge people to get vaccinated, but Flagami resident Carlos Reyes said he is debating whether to immunize his 11-year-old son in seventh grade, when kids are required to get another round of shots. He wonders about the efficacy of vaccines and is dubious of companies peddling them.
“It has been my personal experience that medications are doing nothing but alleviating some of the complaints that we have. I’m applying that thought to vaccines,” said Reyes, 42. “I’m asking myself who’s making them? What is their primary objective? Is it the public’s best interest and health?”
In Florida, parents are allowed to claim a religious exemption from vaccinating their kids. And the number of parents choosing that option has steadily risen for at least 20 years, with 1.7 percent of Florida kindergartners now forgoing immunizations. Columbia County, between Tallahassee and Jacksonville, has the highest rate: more than six percent.
While other counties may have lower overall vaccination rates than Miami-Dade — Okaloosa County in the Panhandle is the worst, with only 87 percent of kindergarteners immunized — public health experts say South Florida remains particularly vulnerable.
The steady stream of tourists and immigrants, many from countries with low vaccination rates, is one contributor, said Dr. Aileen Marty, a professor of infectious diseases at Florida International University who also works with the World Health Organization.
“That absolutely puts us at higher risk,” she said.
Some foreign countries, however, actually have higher vaccination rates than the United States. In Brazil, for example, there is a 99 percent vaccination rate against measles among 1-year olds, according to the WHO.
“Many children around the world have very good immunization rates. In fact, the U.S. lags behind,” said Dr. Jamie Morano, an assistant professor of infectious diseases at the University of South Florida. “Not because of bad policy, but because many parents are opting out.”
Miami-Dade’s health department and public school district embarked on an aggressive information campaign after vaccination rates dipped dangerously low from 2008 to 2012. The rate dropped to about 79 percent in 2010 — the lowest in the state. Officials now say the surprising decline largely amounted to paperwork or coding errors.
While overall rates have improved markedly, in 2013 Miami-Dade had the third-highest rate of kindergartners in the state with temporary exemptions. The public school district includes those children in its official vaccination rate, claiming a rate near 98 percent.
District officials defend that calculation, saying they have developed a tracking system that allows principals to follow individual students, helping ensure that they complete vaccinations. Records show the district is doing a good job of keeping track of students who don’t comply.
“We are the district in the nation that takes in so many new students from, really, all over the world,” said Moore. “So having this in place really ensures a safe learning environment in our schools.”
But while those “temporary” exemptions meet state health requirements to begin school, some experts say they should not be counted in the district’s vaccination rate. The state also doesn’t include them in the official tally.
“Those kids are at risk,” said Marty, the FIU professor. “If they’re not vaccinated, they’re not vaccinated. End of story.”
This article includes comments from the Public Insight Network, an online community of people who have agreed to share their opinions with the Miami Herald and WLRN. Become a source at MiamiHerald.com/insight.
Miami Herald reporter Hannah Sampson contributed to this article.