Delays in receiving vaccinations lead to greater vaccine-preventable disease risk. Timeliness of receipt of recommended vaccinations is not routinely tracked in the U.S., either overall or for populations that have known barriers to accessing routine health care, including lower-income families and children.

Newcomer, et al. (2024) sought to measure vaccination timeliness among U.S. children aged 0 to 19 months, overall and by socioeconomic indicators.

This serial, cross-sectional study analyzed nationally representative data from the 2011 to 2021 National Immunization Survey–Child (NIS-Child), an annual survey of parents, with immunization histories collected from clinicians administering vaccines. The 2020 and 2021 surveys largely reflected vaccinations in the U.S. before the COVID-19 pandemic. Study participants included U.S. children surveyed at ages 19 to 35 months. Data were analyzed from January to August 2023.

The surveys included 179,154 children (92 248 boys [51.2%]); 74,479 (31.4%, weighted) lived above the federal poverty level with more than $75 000 in annual family income, 58,961 (32.4%) lived at or above the poverty level with $75,000 or less in annual family income, and 39,564 (30.2%) lived below the poverty level. Overall, the median (IQR) ADU for the combined seven-vaccine series in the U.S. decreased from 22.3 (0.4-71.5) days in the 2011 survey to 11.9 (0.0-55.5) days in the 2021 survey. The prevalence of on-time receipt of the combined seven-vaccine series increased from 22.5% (95% CI, 21.4%-23.6%) to 35.6% (95% CI, 34.2%-37.0%). Although children with more than $75,000 in annual family income had a 4.6% (95% CI, 4.0%-5.2%) mean annual increase in on-time vaccination, the mean annual increase was 2.8% (95% CI, 2.0%-3.6%) for children living at or above the poverty level with $75 000 or less in annual family income and 2.0% (95% CI, 1.0%-3.0%) for children living below the poverty level.

In this cross-sectional study of NIS-Child data, improvements in vaccination timeliness were observed from the 2011 to the 2021 survey. However, widening disparities by socioeconomic indicators signal that increased efforts to facilitate timely vaccination among children in lower-income families are needed.

Reference: Newcomer SR, et al. Vaccination Timeliness Among US Children Aged 0-19 Months, National Immunization Survey–Child 2011-2021. JAMA Netw Open. 2024;7(4):e246440. doi:10.1001/jamanetworkopen.2024.6440