More and more mid- to high-income parents are choosing not to vaccinate their children.
Some fear vaccines cause autism or other diseases. Some had a bad experience with inoculations themselves or refuse to inject what they consider to be toxic chemicals into their children's bodies. Some believe vaccines are nothing more than a conspiracy by the government and pharmaceutical companies to make a profit.
Many who don't vaccinate - perhaps the largest group - have heard concerns from friends and family and feel conflicted about what to do for their own children.
Understanding why parents don't vaccinate is crucial to reversing the decline in vaccination rates, doctors and medical researchers say. Until parents get facts that ease their concerns, rates will likely continue to drop, increasing the potential for an infectious disease outbreak.
To that end, doctors can play a valuable role in educating parents who don't vaccinate their kids out of convenience or misinformation, says Dr. Arturo Gonzalez, outgoing president of the Arizona chapter of the American Academy of Pediatrics. A proposed state law would require parents to get a doctor's signature and hear the risks of not vaccinating before getting a waiver based on personal beliefs.
If it's considered next session, lawmakers should hear from parents who don't vaccinate so they understand their concerns, said Rep. Cecil Ash, R-Mesa, who introduced the bill.
The decision not to vaccinate boosts the risk that rarely seen infectious diseases such as measles, mumps and polio will infect one child, spread quickly and surge into an outbreak. That would endanger babies too young to be immunized, anyone whose vaccinations didn't take and people with compromised immune systems who can contract infectious diseases even if they're immunized.
The World Health Organization estimates that in 2008, 1.5 million children under age 5 died of diseases vaccines can prevent. The deaths represent 17 percent of global mortality for that age group.
Parents with the means to choose their children's schools often gravitate toward places where families share their views, so unvaccinated kids tend to cluster. A Daily Star investigation in May found that one in three Arizona schools last year had kindergarten classes with vaccination rates so low that children were vulnerable to outbreaks.
Families should get the facts from doctors, Gonzalez says.
"There's always going to be people who, whatever I say or the CDC (Centers for Disease Control) says, they will never vaccinate. That's sad. ... But for those who are not sure of what to do, I think they deserve our version, not Dr. Google."
Too many vaccines
She's not against vaccines, but Tucson mother Margie Wrye is cautious about them.
Wrye, a retired radio announcer in her 40s, has two teenage sons who have never received the hepatitis B vaccine. And when they got their other vaccinations as babies and toddlers, Wrye did not get them all on the schedule the federal government recommends. Instead she spaced out the shots so that her sons wouldn't receive multiple vaccines in one day. Several other people interviewed by the Star said they do the same.
As for the hep B vaccine, Wrye felt it wasn't necessary. Hepatitis B attacks the liver. The virus can cause liver scarring, liver cancer, liver failure and death. The virus is spread when blood, semen or another infected body fluid enters the body of an uninfected person.
"The vast majority of people who get it are IV drug users, or in the medical profession coming in contact with blood products in an intimate way. I didn't see the need for it. My kids were not in that category," Wrye says.
She grew concerned after reading about parents who connected vaccines to autism in their kids. She watched her children closely each time they got an inoculation. They never had any adverse reactions, and she believes they are safer with the vaccines than without. Though the chicken pox vaccine wasn't available when her children were toddlers, she got it for them when they were older after an adult friend nearly died of the disease. Her children are now 15 and 18.
"Reading the stories about autism and vaccinations made me pay close attention to what I was doing with my kids," Wrye says. "If the majority of the population did experience that reaction, we'd have a heck of a problem on our hands."
What the medical evidence says: If parents want to spread out the shots, it's fine as long as children are fully vaccinated by kindergarten.
The CDC says 33,000 children whose mothers did not have hep B were infected with the virus every year prior to the childhood hep B vaccinations.
The natural healer
Tucson naturopathic physician Tevna Tayler used to vaccinate her two children, but changed her mind when she was in naturopathy school.
"We don't know the long-term effects - whether vaccines put people at higher risk for cancer, depression, attention deficit disorder, thyroid problems - modern epidemics," Tayler says. "No one knows what it does to the DNA and immune system. The fact is, even vaccinated children get whooping cough."
Not all naturopaths are against vaccines, but the prevailing viewpoint is that the government's immunization schedule is too aggressive, says Amy Terlisner, a naturopathic physician in Scottsdale and president of the Arizona Association of Naturopathic Physicians.
"If you talk to 10 different naturopaths you are going to get 10 different viewpoints," Terlisner says. "The moderate viewpoint is that there are too many (shots) in the first year compared to 20 years ago. It's about double what I got when I was a baby. There are naturopaths who are completely anti-vaccine, too."
Tayler says she works with each patient on an individual basis and would never direct anyone to avoid all vaccinations unless it's what they want. But when it comes to her own children, she'd rather help her children's own bodies stay healthy, strong and able to fight off infection on their own, without vaccines.
"I'd rather naturally boost the immune system," she says. "In what natural world do you get injected with a strange concoction?"
What the medical evidence says: Well before the onset of medical science, human beings lived without pesticides or chemicals.
But in those times there was malnutrition, infectious disease outbreaks and short life expectancy.
Skeptical about vaccine safety
Arizona State University professor James B. Adams has been researching autism, including its relationship to vaccines, since his daughter's diagnosis 16 years ago.
An engineering professor who is president of the Autism Society of Greater Phoenix, Adams says vaccines can have value, but need to be safer.
Adams stopped vaccinating his daughter, Kimberly, now 20, after her diagnosis. He believes a very small number of children seem to be more vulnerable to vaccines.
"She was autistic early on, but we deeply suspect it was due to the vaccinations. We tracked down her vaccines and they all contained massive amounts of mercury."
Kimberly was vaccinated before the federal recommendation to remove the mercury-derivative thimerosal from childhood vaccines. Most immunizations no longer contain thimerosal, but Adams remains concerned about other preservatives in vaccines, particularly aluminum.
"Unfortunately my major concern is that families are not given an informed consent," he says.
He cites a 2008 case in which the federal government agreed vaccines injured 9-year-old Hannah Poling, who developed autisticlike symptoms after receiving several vaccinations in one day.
Adams says he's heard too many heartbreaking post-vaccine reports of hospitalizations, fevers and regressions in development.
"Is it happenstance that those regressions occur around the time of certain vaccinations? Perhaps, yes. But when I hear symptoms that are occurring within a few hours or days of the vaccination, I give that a lot of credibility."
What the medical evidence says: Since 2001, all vaccines manufactured for use in the U.S. for children ages 6 and younger have contained no thimerosal or trace amounts.
Still, autism rates have continued to climb. A recent report by the CDC places the current rate of autism at one in 88 children.
The true believer
David Stender is an adoring and involved father of four children, the owner of Living Well Chiropractic and a devotee of improving health naturally.
He argues vaccinations are made in part from aborted fetal tissue and tissue of chickens. He says they're pushed so pharmaceutical companies can profit. He believes the reduction of vaccine-preventable diseases resulted from improvements in sanitation and public heath rather than vaccines.
Stender, who lives in Oro Valley and gives speeches on natural healing, is a consumer of alternative medical research, on sites such as www.mercola.com - run by Illinois-based Dr. Joseph Mercola. The site sells natural supplements and posts links to anti-vaccine articles.
"I wish they would look at all the data - not just what is put out by special interests," Stender says. "You can't ignore the money part of the equation. All I want is vaccine choice. If they had their way, they would force you to inject those toxins into your body."
Stender says vaccines didn't eliminate smallpox. He likens smallpox to the bubonic plague, which hasn't been eliminated, but has been significantly lessened through improvements in sanitation. However, bubonic plague is spread by the fleas of rats while smallpox was spread through human contact or contaminated bedding or clothing.
What the medical evidence says: Some childhood vaccines, including MMR and the joint MMR-varicella vaccination, are grown in chicken embryo cultures, the U.S. Food and Drug Administration says.
Some vaccines in the U.S. are manufactured from viruses grown in cell lines originating from aborted fetal tissue obtained decades ago. No new fetal tissue is needed for vaccines, the FDA says.
There has not been a case of smallpox in the world since 1976 and evidence-based medical research says the eradication of smallpox is a direct result of mass vaccinations.
Changed by autism
The changes began hours after her son's second inoculation against measles, mumps and rubella.
"He ran a fever, he was fussy and I chalked it up to teething," Kimberly Haslett says of then-16-month-old Jarrett. "He became a totally different child overnight. He was irritable the next day. He was eating a plate of spaghetti and he said, 'All done.' I didn't take it away and he repeated, 'All done' and flung the whole plate against the wall. That was not him at all."
Jarrett eventually stopped giving her kisses, stopped talking. He began hitting his sister. The glow in his eyes faded. Then came the diagnosis: autism.
The scientific data says otherwise, but Haslett, a Tucson insurance agent, is certain the second dose of MMR vaccination is to blame. Jarrett, now 14, has not had a vaccine since.
Haslett, 55, knows parents who shun vaccines are often labeled as misguided and uninformed.
"I had never questioned vaccines. I got them for my daughter and was getting them for my son. But as the months went on I realized I had a whole different child. Something was really wrong."
Her belief is that some children are more sensitive to vaccines, and in Jarrett the vaccination caused an autoimmune reaction that triggered his autism.
"Until you've walked a mile in my shoes, don't judge me. My child will never live on his own and I have a lot of guilt about that," she says, her voice filling with emotion. "I'll never vaccinate again."
What the medical evidence says: Former British surgeon Andrew Wakefield's link between MMR and autism appeared in a prestigious British medical journal in 1998. Several co-authors removed their names from the study in 2004 after learning Wakefield was paid by a law firm planning to sue vaccine manufacturers. The medical journal retracted the study in 2010.
"There is no credible scientific proof linking vaccines with the onset of autism," says Dr. Sean Elliott, a pediatric infectious disease expert at the University of Arizona Medical Center.
Bad reactions fueled fear
Tucson caregiver Sean Badaracco has no plans to vaccinate his 4-year-old daughter again.
The last time Devanie had a vaccination she was 15 months old, and he says it made her ill.
Badaracco, 25, says he had his own violent reaction to a vaccination when he was 17. After getting a dose of hepatitis B vaccine, he turned white, became shaky and felt fatigued, he says.
Watching the 2008 anti-vaccination documentary "Vaccine Nation" three years ago confirmed his suspicions.
"The facts are that there's an epidemic of brain disorders - autism, ADHD (attention deficit hyperactivity disorder). The facts are the facts," he says. "People just aren't educated."
Badaracco doesn't believe he's putting his daughter at risk by leaving her unvaccinated. Rather, he says, he's protecting her.
"They do too many vaccines at once. I was not going to do that to my daughter," he says. "These vaccines are a multimillion-dollar business."
What the medical evidence says: There are medical risks to vaccinating, and parents of certain medically compromised children need to talk to their pediatricians before getting inoculated. They include children who have had a severe reaction to a vaccination in the past.
Scarred by experience
Tucson literary publicist and editor Lynn Wiese stopped vaccinating her children when one was a baby and the other a toddler.
Her decision came after years of research starting in 1986, when her husband developed a tingling in his fingertips four months after a routine tetanus vaccine.
Seven years and eight neurologists later, he was diagnosed with demyelinating peripheral neuropathy, which results in nerve and muscle degeneration. Doctors didn't know how he acquired the condition and they didn't have effective treatments to offer, she says. He gave up his favorite sport, golf. It became difficult to grasp objects and pick them up.
During her research, Wiese read a magazine article that said the disease was a possible side effect of the tetanus vaccine. She spent five years studying and ended up writing a book called "Holistic Parenting" that includes a chapter about vaccines.
"I was astounded at how much information was out there raising red flags about the safety and efficacy of vaccines," she says. "Back in 1997 we were involved in a Waldorf school where 50 percent of parents didn't vaccinate their kids. I don't think they were careless. I think they thought through this issue carefully."
Her children are now in college.
Wiese, who has relied on homeopathy for more than 20 years, says the success of homeopaths has been ignored in the U.S., but warrants more attention.
"Whether or not to vaccinate is a major parenting decision. For me, challenging the immune system with vaccines wasn't in my children's best interest."
What the medical evidence says: Minor vaccine reactions are fairly common. About one in three patients gets a headache or upper-respiratory infection and one in 100 is affected by fever. But serious adverse reactions - including seizures, inflammation of the brain and fainting - are rare. Nearly 3,000 people have been compensated by the government for vaccine reactions, out of millions of vaccines given.
The risks of the diseases vaccines prevent are well-known - paralysis, neurological devastation and death, among others.