With school about to start, many parents in the region are scrambling at the last-minute to get the required vaccinations. But some parents still have reservations about safety, and find ways to opt out of the immunizations.

That's a concern to health officials, since some of these vaccine-preventable illnesses are making a comeback. This year, there were five cases of measles in the state, which was more than occurred in the previous eight years combined. Nationwide, the Centers for Disease Control and Prevention, reported that measles hit a 20-year high in 2014.

Other diseases that have resurfaced in recent years include pertussis, or whooping cough, which hit a 10-year high in Connecticut in 2012, with more than 180 cases.

Pertussis levels in the state have fallen since then, but the resurgence of these illnesses speaks to the importance of vaccines, said Dr. Kathy Kudish, epidemiologist with the Connecticut Department of Public Health.

"We just want to remain vigilant and try to keep these disease from spreading," she said. "Vaccine-preventable diseases remain a threat."

Opting out

More Information

Vaccine exemptions
The numbers of Connecticut children entering school with exemptions for vaccines:
Religious exemptions: 316
Medical exemptions: 149
Total: 465

Religious exemptions: 477
Medical exemptions: 245
Total: 722

Religious exemptions: 318
Medical exemptions: 148
Total: 466

Religious exemptions: 380
Medical exemptions: 166
Total: 546

Religious exemptions: 348
Medical exemptions: 152
Total: 500

Religious exemptions: 466
Medical exemptions: 162
Total: 628

Religious exemptions: 455
Medical exemptions: 140
Total: 595

Religious exemptions: 579
Medical exemptions: 185
Total: 764

Religious exemptions: 810
Medical exemptions: 246
Total: 1,056

Religious exemptions: 910
Medical exemptions: 243
Total: 1,053

By state law, children must receive doses of several vaccines -- including those guarding against pertussis and measles -- to be admitted to a licensed child-care program or school. Unvaccinated children can only enter school if they submit a statement of exemption.

In Connecticut, there are two types of vaccine exemptions, medical and religious. With a medical exemption, parents or guardian need to show documentation from doctor that there's a medical reason that a child can't get immunized.

These can include an allergy to a vaccine, or a disease that weakens the immune system, such as HIV. For religious exemptions, the threshold is much lower, as parents just need to sign a form saying that vaccinations are contrary to the family's religious beliefs.

Kudish said a little more than 1 percent of students entering kindergarten request an exemption, and the majority of children in Connecticut receive the proper vaccinations.

However, the number of exemptions in the state has grown exponentially over the past decade. In 2003, the state reported that 465 students entering kindergarten or seventh grade had claimed exemptions. By 2012, the latest year for which data was available, there were 1,153 such exemptions, most of them religious exemptions.

Though some of these exemptions are valid, parents often have other, non-religious reason for getting them.

"Some parents do decide not to vaccinate, whether it's because they think their child is getting too many vaccines or they're worried about side effects or (a perceived link) to autism," said Dr. Harris C. Jacob, chairman of pediatrics at Bridgeport Hospital.. "There are a variety of reasons."

Health officials have battled the concern about autism for years.

The issue was sparked by a 1998 study featured in the medical journal The Lancet, which was retracted two years later, after the doctor who led it admitted he had received money from a lawyer suing vaccine manufacturers. In 2004, a report from the Institute of Medicine concluded there is no link between autism and the vaccine.

Weighing risks

Still, some parents remain reluctant to vaccinate their children. That reluctance has contributed to the return of such illnesses as measles, said Dr. Michael Parry, Stamford Hospital director of infectious diseases. There is "absolutely no question" that when fewer people get vaccinations the chance of exposure to illness increases, he said.

"When exemption rates go up, that's when you start to see isolated outbreaks start to occur," Parry said.

Jacob agreed. He said a lot of parents who eschew vaccinations depend on the concept of "herd immunity" to protect their children from illnesses. In other words, they expect that, because everyone is vaccinated against a disease, their child won't be exposed.

"If every child in the U.S. were vaccinated against measles except one, then, yes, that child would be safe," Jacob said.

But, he said, when you have multiple unvaccinated people, the risk for exposure to illness increases.

That's why it's so important for children to get vaccinated, said Dr. Toni Lyn Salvatore, medical director of Greenwich Hospital's pediatric center.

"I was speaking to a parent the other day who was worried about vaccinations," she said.

"The problem with going online and reading horror stories about vaccines is that most of these people don't remember the mortality and morbidity rates of certain disease that we had before vaccines."

For instance, polio, an illness largely eradicated by vaccines, can cause paralysis, difficulty breathing, and, in some cases, death. Other vaccine-preventable diseases are potentially fatal, including measles and whooping cough.

Even when they're not deadly they can have other serious consequences, said Bernice Bova, nursing supervisor for the Stratford Health Department.

"You can lose a limb from meningitis," she said, referencing another illness that is vaccinated against. "Mumps can lead to sterility."

Heather Henning, public health nurse for the Trumbull Monroe Health District, agreed. "These illnesses really can be very debilitating," she said.

"They can make you very sick."