Back-to-school preparations always bring a rush of parents and children to the Dallas County Health and Human Services immunization clinics. For the Dallas ISD student population of more than 160,000, only 486 students were not vaccinated for reasons of conscience or religious belief.

Trend of no vaccines worries doctors Parents of school-age children in Texas quickly learn the choices: Get your kids vaccinated according to the state-mandated schedule or officially opt out of the vaccines. The vast majority of parents choose the vaccines. But the small number opting out, in Texas and across the country, has grown over the past few years. It has grown large enough that illnesses once thought to be all but eliminated in the United States are flaring up in short outbreaks. Earlier this year, the fear of a measles outbreak was triggered in North Texas when Plano ISD reported one case in a student at Schell Elementary School in Richardson. The child, who had not been vaccinated, had recently returned from a visit to an unidentified foreign country where measles is still common. Nobody else caught the illness from the child. The Dallas Morning News decided to find out how likely it is for students at other North Texas schools not to have been vaccinated. A selection of districts was asked to provide campus-level information about the number of students whose parents opted out. The results are generally reassuring to anybody worried about significant outbreaks. Exemption rates at area schools Results from a Dallas Morning News request for exemption data shows that, for the most part, area schools are fairly well-protected from outbreaks. By address By district By name Enter an address Find it! Search for a school View by district Allen Dallas Frisco Garland McKinney Mesquite Plano Richardson School rank compared to all schools surveyed: Fewer exemptions More exemptions Fewest exemptions Most exemptions For the entire Dallas ISD student population of more than 160,000 students, for instance, only 486 students were not vaccinated for reasons of conscience or religious belief — about three-tenths of 1 percent of the students. But there are some clusters: Eduardo Mata Elementary has 23 students not vaccinated, about 6 percent of the students on that campus. Booker T. Washington High School for the Performing and Visual Arts has 25 nonvaccinated students, about 3 percent of the total. There are other pockets of higher nonvaccination rates at some schools in North Texas. In Plano ISD, for instance, 20 students at Aldridge Elementary opted out this year — 3.5 percent of the campus. Norton Elementary School in Allen ISD has 20 students — 3.7 percent. Bledsoe Elementary in Frisco has 37, almost 5 percent. Those small numbers match what is found mostly across the country. But there are places where the rates of refusal are much higher. An outbreak of measles in California in 2014, associated with visitors to Disneyland, spread mostly to people who had not been vaccinated. More than 150 people got sick; 17 were hospitalized. And last year, California passed a law ending the conscience provision from its vaccination requirements. A study of measles and pertussis outbreaks was published last month in the Journal of the American Medical Association. It found that more than half the measles cases in the outbreaks studied showed up in people not vaccinated — even though they represent a tiny fraction of the total population. For pertussis, a.k.a. whooping cough, the data was not as clear because the vaccine is not as effective. But even for that illness, the percentage of cases in undervaccinated children was dramatically high. 4 diseases on the rise at-a-glance 1 Measles Symptoms High fever, runny nose, cough, red and watery eyes (conjunctivitis), and sore throat. Two or three days after symptoms begin, tiny white spots (Koplik spots) may appear inside the mouth. Three to five days after symptoms begin, a rash breaks out. It usually begins as flat red spots that appear on the face at the hairline and spread downward to the neck, trunk, arms, legs and feet. Small raised bumps may also appear on top of the flat red spots. The spots may become joined together as they spread from the head to the rest of the body. When the rash appears, a person's fever may spike to more than 104 degrees. Contagion The symptoms of measles generally appear about seven to 14 days after a person is infected. Infected people can spread measles to others from four days before through four days after the rash appears. Measles is so contagious that if one person has it, 90 percent of the people close to that person who are not immune will also become infected. Transmission Coughing and sneezing. The measles virus can live for up to two hours in an airspace where the infected person coughed or sneezed. If other people breathe the contaminated air or touch the infected surface, then touch their eyes, noses, or mouths, they can become infected. Complications Diarrhea

Ear infections , which in some cases, can result in permanent hearing loss.

, which in some cases, can result in permanent hearing loss. Pneumonia (infection of the lungs)

(infection of the lungs) Encephalitis (swelling of the brain)

(swelling of the brain) Subacute sclerosing panencephalitis (SSPE) is a very rare but fatal disease of the central nervous system that results from a measles virus infection earlier in life. SSPE generally develops seven to 10 years after a person has measles, even though the person seems to have fully recovered from the illness. 2 Mumps Symptoms Fever, headache, muscle aches, tiredness, loss of appetite followed by swollen salivary glands under the ears on one or both sides which can cause puffy cheeks and swollen jaw. Some people who get mumps have very mild or no symptoms, and often they do not know they have the disease. Contagion Symptoms typically appear 16-18 days after infection, but this period can range from 12-25 days after infection. Transmission Saliva or mucus from the mouth, nose, or throat. An infected person can spread the virus by coughing, sneezing or talking, sharing cups or eating utensils with others, and touching objects or surfaces with unwashed hands that are then touched by others. Complications Deafness

Inflammation of the testicles (orchitis) in males who have reached puberty; rarely does this lead to fertility problems.

(orchitis) in males who have reached puberty; rarely does this lead to fertility problems. Inflammation of the brain (encephalitis)

(encephalitis) Inflammation of the tissue covering the brain and spinal cord (meningitis)

(meningitis) Inflammation of the ovaries (oophoritis) and/or breasts (mastitis) in females who have reached puberty 3 Pertussis (whooping cough) Symptoms Runny nose, low-grade fever (generally minimal throughout the course of the disease), mild, occasional cough, apnea – a pause in breathing (in babies). In its early stages appears to be nothing more than the common cold; it is often not suspected or diagnosed until the more severe symptoms appear, such as paroxysms (fits) of many, rapid coughs followed by a high-pitched “whoop,” vomiting during or after coughing fits and exhaustion after coughing fits. Contagion The symptoms of measles generally appear about seven to 14 days after a person is infected. Infected people can spread measles to others from four days before through four days after the rash appears. Measles is so contagious that if one person has it, 90 percent of the people close to that person who are not immune will also become infected. Transmission Coughing, sneezing, very close shared breathing space. Many babies who get pertussis are infected by older siblings, parents or caregivers who might not even know they have the disease. Infected people are most contagious up to about two weeks after the cough begins. Antibiotics may shorten the amount of time someone is contagious. Complications Babies and children: Pneumonia (lung infection)

(lung infection) Convulsions (violent, uncontrolled shaking)

(violent, uncontrolled shaking) Apnea (slowed or stopped breathing)

(slowed or stopped breathing) Encephalopathy (disease of the brain)

(disease of the brain) Death





Teens and adults: Weight loss

Loss of bladder control

Passing out

Rib fractures from severe coughing 4 Chickenpox Symptoms Fever, tiredness, loss of appetite; a headache may appear 1-2 days before a rash that turns into itchy, fluid-filled blisters that eventually turn into scabs. The rash may first show up on the face, chest, and back then spread to the rest of the body, including inside the mouth, eyelids or genital area. It usually takes about one week for all the blisters to become scabs. Contagion A person with chickenpox can spread the disease from one to two days before they get the rash until all their chickenpox blisters have formed scabs (usually five to seven days). It takes about two weeks (from 10 to 21 days) after exposure to a person with chickenpox or shingles (a related virus) for someone to develop chickenpox. Transmission Touching or breathing in the virus particles that come from chickenpox blisters and possibly through tiny droplets from infected people that get into the air after they breathe or talk. Complications Bacterial infections of the skin and soft tissues in children including streptococcal infections

of the skin and soft tissues in children including streptococcal infections Infection or inflammation of the brain (encephalitis, cerebellar ataxia)

(encephalitis, cerebellar ataxia) Bleeding problems

Blood stream infections (sepsis)

(sepsis) Dehydration

Death SOURCE: Centers for Disease Control and Prevention Relatively low rates of unvaccinated children still worry health officials. Even though the total numbers remain small, the number of serious cases is growing. Paradoxically, that’s because most American children are getting the vaccines. And here’s why: Some diseases make people sicker when they catch them while older. A couple of generations ago, measles and chicken pox were most often the bane of small children. Not anymore, said Nina Fefferman, an associate professor at Rutgers University and an expert in modeling the spread of infectious diseases. Fefferman uses a candy analogy to explain this concept, with candy representing a vaccine-preventable disease such as measles.


“Imagine there are a couple of people wandering around handing out candy. When someone hands you candy, you can take it and pass it along. The fewer people there are wandering around with candy means it’s going to take you longer to get your hands on the candy,” she said. “You’ll be older by the time you get candy.” Are any of the local numbers large enough that school or public health officials are concerned about mass outbreaks? Not at this point. How much larger would they need to get before there are serious health worries? That depends on a number that disease experts call the R0. The science of immunity Based on age and grade, Texas public school students are required to be vaccinated for diphtheria, tetanus, pertussis, polio, measles, mumps, rubella, hepatitis A and B, varicella and meningococcal disease. But not all diseases are equally infectious. Just one person with measles will typically pass the infection on to 12 to 18 other people — about as infectious as any disease can be. A person with mumps, by contrast, will infect about four to seven people. That number, the average number of people a person infects, is known as the basic reproduction number, or R0. The higher the number, the faster an illness can spread. Vaccines can lower the R0 of a disease like putting a water-filled moat around a fire keeps flames from spreading. If a child with measles goes to school while infectious, he is far less likely to cause an outbreak if most of his classmates are vaccinated. The benefit given to everybody once enough of the population is immunized is called “herd immunity.” For measles, the percentage of the “herd” that needs to be immune is between 83 to 94 percent. The proportion of kids who need to be vaccinated to stop an outbreak of mumps is lower — 75 to 86 percent — because mumps is less contagious than measles and has a lower R0. “That’s the beauty of herd immunity. The idea that as long as a sufficient number of people around you are vaccinated you are protected,” Fefferman said. What is herd immunity? Herd immunity is the proportion of the population that is protected against a disease through vaccination or previous infection. People who are immune to a disease provide indirect protection to unvaccinated individuals by breaking the chain of transmission when a disease enters a population.

Not immunized, sick and contagious Not immunized, healthy Immunized and healthy When no students have been immunized, a large number of the student population are vulnerable to contagious diseases. As more students are immunized, the potential for transmission is reduced. When most of the student population is immunized, it becomes more difficult for the contagion to spread. But Fefferman is frustrated that doctors rely on the concept of herd immunity to persuade parents to vaccinate their children. “Saying to parents, ‘Well, what about other people’s kids?’ isn’t going to get you far,” she said. “If you’re talking to parents who are concerned about the safety of vaccinations, then altruism isn’t a compelling argument. Clearly it’s not, because that strategy is failing.” Instead, Fefferman says, doctors and parents should focus on the fact that some diseases, such as measles and chickenpox, are causing more severe illness now than a generation or two ago.