Fewer Kids Up to Date on Shots

Vaccination delays and parent refusals of vaccine are increasing among children

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) The safety of the CDC immunization schedule was recently upheld, but some parents continue to be concerned about vaccine safety. This concern may put their children's health at risk.

A recent study looked at the rates of children who had not received all their shots according to the schedule by the Centers for Disease Control and Prevention (CDC).

The researchers found that rates of children without all their vaccinations are slowly increasing. This could put these children at higher risk for getting infectious diseases.

Children with fewer vaccinations tended to visit the doctor less but the hospital more, the researchers found.

"Follow the CDC immunization schedule."

The study, led by Jason M. Glanz, PhD, at the Institute for Health Research with Kaiser Permanente Colorado in Denver, aimed to understand the different healthcare patterns in children who were fully vaccinated versus not fully vaccinated.

The researchers used the Vaccine Safety Datalink to analyze data on 323,247 children born between 2004 and 2008.

This database includes detailed information on vaccinations, health conditions and demographics for children in eight managed care organizations in the US.

First, the researchers calculated how many total days, on average, children went under-vaccinated. Being under-vaccinated means that children have received some of the required vaccinations for their age, but they have not received all of them according to the CDC schedule.

The researchers grouped the under-vaccinated children into two groups: those under-vaccinated for any reason at all (forgetfulness, missed appointments, medical reasons, etc.) and those under-vaccinated because their parents chose not to get them certain vaccines.

The researchers then compared each of these children in both groups to fully vaccinated children, matched by their birth date, gender and the healthcare organization they were part of.

This way the researchers could find out what patterns might be different among children fully vaccinated, those under-vaccinated because of their parents' choice and those under-vaccinated for other reasons.

Just under half the children (49 percent) in the study were under-vaccinated for at least one day before age 2. The average length of time children went under-vaccinated across the whole study was 36 days, but this number increased from 28 days in 2004 to 44 days in 2008.

The researchers found that the rate of under-vaccination increased over time as well, from 41.8 percent in 2004 to 54.4 percent in 2008.

Among those under-vaccinated, an estimated 13 percent of the children did not receive vaccines because of parental choice.

Children who were under-vaccinated had a slightly lower rate of doctor visits than children who had received all their appropriate vaccines for their age.

However, under-vaccinated children had higher rates of hospital admissions – about 20 percent higher – compared to children with all their vaccines up to date.

When the researchers looked specifically at children whose parents had chosen not to give them certain vaccines, the researchers found that these kids had slightly lower doctor visit rates, fewer emergency department admissions and fewer hospital admissions than children who were fully vaccinated.

These lower rates among children under-vaccinated by choice did not mean the children got sick less. The parents may have chosen not to see a doctor when the children were sick.

"For example, published survey data have shown that parents who choose not to have their children vaccinated are less likely to trust healthcare professionals and more likely to use complementary/alternative medicine providers than are parents who have their children fully vaccinated," the researchers wrote.

The researchers also noted that parents who delay or refuse vaccines because of unfounded concerns about vaccine safety "may be placing their children at increased risk for infectious diseases that are almost 100 percent preventable with vaccination."

Thomas Seman, MD, a pediatrician at North Shore Pediatrics in Danvers, Mass. and a dailyRx expert, said this issue is a serious one his practice deals with on a nearly daily basis.

"There does seem to be a serious distrust among some parents with the recommendations for immunizations," Dr. Seman said. "Part of the reason may be that there are many new parents who have only heard the name of the diseases, and some have not even this, and have never seen the devastation from these diseases."

He noted that vaccination is even more important today when there are more children around who may have weaker immune systems.

"With improved medical care there are a greater number of children surviving earlier prematurity, cancer, genetic disorders and birth defects more children are needing vaccines since they are at a weakened state," Dr. Seman said. "By parents not immunizing their children, not only are they putting their own child(ren) at risk, but also those of the other children."

A commentary published with this article noted that another increasing trend is the use of alternative vaccination schedules that are different from the CDC one.

Whether published in a book or used by different pediatricians, authors Douglas J. Opel, MD, MPH, and Edgar K. Marcuse, MD, MPH, noted that "none of these alternative schedules have been tested for their safety and efficacy."

The doctors suggested that studying the safety and effectiveness of these other schedules may be a good idea since more parents appear to be using them, against the recommendations of the CDC.

Dr. Seman noted other challenges related to "alternative" vaccination schedules.

"They are hard to keep track of, thereby increasing the chance of missed doses and further adding to the problem," Dr. Seman said. "Not only does this place the child at risk, but many school systems do not accept altered schedules as reason for incomplete vaccination, thus requiring the child to get many at a time as a way of  'catching them up' prior to going to school."

The study was published January 21 in the journal JAMA Pediatrics. The research was funded through a subcontract with America’s Health Insurance Plans with the Centers for Disease Control and Prevention. The authors declared no conflicts of interest.

Reviewed by: 
Review Date: 
January 21, 2013
Last Updated:
January 26, 2013