Many Toddlers Improperly Vaccinated

< Apr. 30, 2008 > -- New statistics reveal that more than a quarter of American toddlers may be under-vaccinated.

The study of children (aged 19 months to 35 months) demonstrated that missed vaccinations account for around two-thirds of non-compliance with official recommendations.

However, doses taken at the wrong time are also an issue with compliance, according to a study conducted by the US Centers for Disease Control and Prevention (CDC).

Wake-up Call for Immunizations

Immunization delays place children at risk for a variety of vaccine-preventable diseases such as measles, mumps, and chicken pox. However, immunization rates in the US are decent, experts state.

"Part of it depends on how you are slicing and dicing this," says Dr. Robert Frenck, professor of pediatrics at Cincinnati Children's Hospital and a committee member of the infectious disease committee of the American Academy of Pediatrics (AAP).

"If you look at children going into kindergarten [four to six years old], our immunization rates are as high or higher than they've ever been."

According to the CDC's yearly National Immunization Survey (NIS), the percentage of American children 19 to 35 months of age who have received the recommended series of childhood vaccines was 77 percent in 2006.

"This is a little bit of a wake-up call - not a huge one - that you need to make sure to do the best you can to get children vaccines when they're supposed to get them," adds Dr. Paul Offit, chief of infectious diseases at the Children's Hospital of Philadelphia. He stresses that "kids may catch up [when they're older]."

Must Follow Guidelines Precisely

Parents and kids face a complex schedule of vaccinations in the first few years of life. Some might even say it is a bit of a nightmare.

This study was based on doses kids received in 2003 and 2004, at which time an 18 month old toddler should have received about 14 shots making up several different vaccines. Today even more shots are recommended.

For the study, researchers reviewed vaccination histories for more than 17,500 US children aged 19 months to 35 months.

An estimated 72 percent of children in this age group finished the standard vaccination series. The results indicated that the compliance of vaccinations was lower than before (by 9 percentage points) taking into account that more than just counting missing doses was done.

Nineteen percent of children were missing one or more doses of vaccines. But eight percent had received an "invalid" dose, meaning it was given when the child was too young or too close to the previous dose.

About three percent of the sample had their last hepatitis B vaccine too early (before six months duration). Some also received their measles vaccine while still protected by their mother's antibodies. Another three percent received serial doses of one vaccine too close together.

For 50 years, the success of the vaccination program has been measured by whether or not children received the required number of doses.

"[But] the official recommendations for vaccination include more than just number of doses," says Dr. Elizabeth Luman, lead author of the study and an epidemiologist at the CDC's National Center for Immunization and Respiratory Diseases. They also include specific age recommendations, multiple doses, at different time intervals.

Parents and Physicians - Remain Vigilant

"If children receive vaccines too close together or too early, they're not as likely to be protected, and if you have a lot of that, then you're more likely to have disease outbreaks," Dr. Luman says.

One reason for lack of strict adherence to the vaccine schedule may be a fading awareness among today's parents of what the diseases these immunizations are protecting children from. Dr. Frenck says he remembers seeing a childhood friend in an iron lung, the result of polio.

"It scared me to death," he says. "Kids these days, and probably most adults, don't even known what an iron lung is - and that's because of immunization."

So far, smallpox has been completely eliminated as a worldwide threat, thanks to immunizations, while much progress has been made with measles and polio.

"People just need to keep their vigilance up," Dr. Frenck says. "We need to continue to review shot records and to go over it with parents whenever they come in. Opportunities for vaccination are missed a lot of times when kids come in for one reason or another, and we don't look at the immunization record. We need to continue to try to immunize kids whenever we have the opportunity."

Please consult your physician for more information.