Published January 14, 2015
More U.S. kids are fully immunized against common childhood illnesses, and disparities in vaccine coverage among socioeconomic groups are shrinking, a new study from the Centers for Disease Control and Prevention shows.
While the findings are "very good news," according to Dr. Elizabeth T. Luman, an epidemiologist at the CDC in Atlanta, Georgia, and co-author of the new study, "we're still not there yet."
In 2008, she and her CDC colleague Dr. Zhen Zhao note in their report, the only group to meet the Healthy People 2010 goal of 80 percent coverage were children with no brothers and sisters.
Luman and Zhao looked at data on immunization for 185,516 children 19 to 35 months old between 2000 and 2008 to examine trends in vaccine coverage. During a child's first 18 months, recommended vaccines include diphtheria-tetanus-pertussis (at least four doses), poliovirus (three doses), measles-mumps-rubella (one dose), hepatitis B (three doses), Haemophilus influenza type B (three doses) and varicella (one dose).
In 2000, Luman and Zhao found, children living below the poverty line were significantly less likely to have received all of the recommended vaccines, as were those whose mothers hadn't finished high school, those with unmarried moms, and those with mothers younger than 30.
Children who received their vaccines from a public provider — such as a government clinic, for example — were less likely to be covered than those who got their shots from a private provider, such as a pediatrician's office. While these disparities persisted through the study period, they did get smaller, and racial and urban/suburban/rural disparities were no longer statistically significant by 2008.
Children without siblings were also more likely to be fully immunized than those with at least one brother or sister; some people, Luman noted, attribute this to the "Kodak syndrome," in which oldest kids have a lot more photos in the family album than their younger siblings.
"It's probably a logistics issue," she added, noting that it can simply be more difficult for families with more than one child to get everyone vaccinated on time.
Vaccine coverage in 2000 ranged from 47 percent for children treated by public providers to nearly 60 percent for only children. In 2008, 72 percent of children with public providers were fully immunized, as were nearly 81 percent of only children.
Much of the drop in disparities can be attributed to the Vaccines for Children program, which offers free immunizations for children who don't have insurance that covers vaccines, Luman said.
"There has also been an increased awareness of the need to identify children who are at risk of under vaccination, and for physicians to make sure that they place extra emphasis on getting them in to get vaccinated," she added.
But, she concluded, there's still plenty of room for improvement. "Additional work is needed to make sure that the underserved groups of children are vaccinated and protected against vaccine preventable diseases."