NBC NEWS- A new study released by the Centers for Disease Control points to a disturbing trend when it comes to our children and their immunizations.

Kids may be getting the vaccines they need, but may not be getting those protective shots at the right times.

Pediatricians say the new numbers from the CDC are the best evidence yet that American kids need a shot in the arm when it comes to their vaccination schedules.

"There are a number of people that aren't getting the vaccines on time," warned Vanderbilt University's Dr. Kathryn Edwards.

The CDC research released Tuesday indicates 28 percent of children between 18 months and three years old are out of sync with the government's immunization guidelines.

Postponing or missing a dose could be dangerous, even potentially deadly.

"These diseases, if we don't vaccinate, will come back with severity and intensity," warned Dr. Edwards.

Jennifer Jefferies understands the importance not only of the vaccines, but of sticking to the schedule as well, though she admits it's tough to chase 18-month-old Meghan and always pay attention to the calendar.

"The best thing to do is when I leave today, make the appointment for our next check-up, which will be two years," she said.

Remembering, according to doctors and scientists with the CDC, could be one of the most important steps toward a healthy future for our children.