About 42% of young children were not up to date on vaccinations, researchers found.
The new study is one of two released today in Pediatrics looking at vaccination. The other explores pediatricians’ views on the Vaccines for Children (VFC) program, which provides vaccines to low-income and uninsured children.
Researchers analyzed vaccination data on more than 15,000 children ages 19-35 months from the 2014 National Immunization Survey. They included coverage at birth, 2 months, 4 months, 6 months and 12-19 months, allowing some flexibility when determining whether children were being vaccinated on schedule. They also included rotavirus and hepatitis A vaccinations, which typically aren’t included in determining whether children are up to date.
By 19-35 months, about 58% of children were up to date on vaccinations, according to “Adherence to Timely Vaccinations in the United States,” (Hargreaves AL, et al. Pediatrics. Feb. 21, 2020, https://pediatrics.aappublications.org/content/early/2020/02/19/peds.2019-0783).
Looking more closely at when children received each vaccine, the team found about 63% followed the recommended schedule, 23% followed an alternate schedule and 15% had an unknown pattern.
Children were more likely to follow an alternate schedule if they were not the firstborn or if they had moved out of state. Low-income children who were black or multiracial were more likely to follow an alternate schedule than those who were white and above the poverty line, according to the study.
Being from a low-income family, moving out of state and receiving vaccines from a public facility also were linked to not following a recognizable pattern.
"This combination of factors suggests that many parents in this category may be attempting to adhere to a recommended schedule but, because of external circumstances, fall behind on the appointments required to maintain a recommended schedule," authors wrote.
Children were four times more likely to be behind if they were following an alternate schedule and twice as likely to be behind if they had an unknown schedule compared to children following the recommended schedule, according to the study.
“Vaccine schedule adherence patterns are strongly associated with up-to-date status, and future research should be focused on identifying the parent actions and circumstances that increase the likelihood of deviating from the recommended schedule,” authors said.
In another study, researchers looked at survey responses from 372 AAP members regarding the VFC program.
About 86% said they participated, 9% never took part and 5% were previous participants, according to “Pediatricians’ Experiences with and Perceptions of the Vaccines for Children Program,” (O’Leary ST, et al. Pediatrics. Feb. 21, 2020, https://pediatrics.aappublications.org/content/early/2020/02/19/peds.2019-1207).
Some of the pediatricians not participating in VFC said they did not participate in Medicaid or have enough low-income patients. They also cited hurdles like record-keeping requirements and having to keep separate stocks of vaccines. The latter reasons also were cited by participants who have considered leaving the program. Those pediatricians also cited unpredictable supplies and inadequate payment.
Still, most said the program was worthwhile because of the benefit to low-income children and the opportunity to vaccinate these children in the medical home.
Authors said pediatricians’ support of the program is crucial.
“Action at the state and federal levels to monitor these concerns and ameliorate them when feasible will be important to the ongoing success of the VFC,” they wrote.