COVID-19 Vaccination Intentions for Children With Medical Complexity

This cross-sectional survey was conducted from June to August 2021 at an academic medical center in the Midwest, as part of the National Institutes of Health’s Rapid Acceleration of Diagnostics-Underserved Populations (RADx-UP) return-to-school initiative. CMC were defined as children ages 5 to 17 years with at least 2 encounters at our medical center in 2020 and at least 1 complex chronic condition (CCC), defined as any medical condition expected to last at least 12 months and involve 1 or more different organ systems severely enough to require specialty care and likely hospitalization at a tertiary care center.⁶  All self-identified English- or Spanish-speaking primary caregivers of CMC attending school before March 2020 with an address available in the electronic medical record were eligible. The survey instrument was composed of items from the National Institute of Health’s RADx-UP common data elements library, which included standardized questions about COVID-19 vaccination acceptance in addition to demographics and health history.⁷  The mail survey was administered by the university’s survey center. Eligible participants received a $5 preincentive with each mailing and a $50 completion incentive. Up to 3 attempts were made to reach participants.

The binary outcome “vaccination intent” was defined as either (1) responding “very likely” to the question, “How likely is your child to get an approved COVID-19 vaccine when it becomes available?” or (2) reporting receipt of at least 1 COVID-19 vaccine dose for their child. At the time of the survey, COVID-19 vaccines were authorized only for those 12 years of age and above. Predictor variables included demographics, health status, and vaccine perceptions. As previous studies have underscored racial and ethnic disparities in morbidity and mortality from COVID-19 and in COVID-19 vaccine acceptance, we included this variable in our analyses.^8,9  Additional demographic variables included age (caregiver and child), sex (child), household income, highest education level, and insurance (public, private, none). Health status variables included caregiver vaccination status, number of CCCs (1 vs >1), hospitalizations in the previous year (0 vs 1 or more), and expected severity of COVID-19. In addition to vaccination intent, questions regarding vaccine perceptions from the RADx-UP common data elements library describe reasons caregivers would or would not vaccinate their child (“Which of the following would be reasons you would vaccinate your child?”).

Bivariate followed by multivariable logistic regression models estimated associations between vaccination intent and covariates. Covariates with statistically significant bivariate associations with vaccination intent were included in the multivariable model: child’s age, number of hospital encounters, insurance type, and vaccine perceptions. Additionally, a priori selected variables informed by previous literature⁴  were included: household income, race and ethnicity, highest education level, number of CCCs, and expected severity of COVID-19. Parental vaccination status was considered as a covariate because of its high correlation with vaccination intent, but was ultimately removed from the model because of concern for collinearity.

Further analysis used χ² tests to assess differences of respondents and nonrespondents, using available data from the eligible cohort creation. Analyses were conducted in SASv.9.4. P values <.05 were considered statistically significant. Consent was obtained by mail and the study was approved by the university’s institutional review board.

Of 2977 eligible families, 1330 responded (44.7%). Respondent and child characteristics are summarized in Table 1. Caregivers were median (interquartile range), 43 (39–48) years old with varied education and income levels. Sixty-one percent of caregivers had private insurance for their child, whereas 37% had either private and public insurance, or public insurance only. Within CMC, 29% had 2 or more CCCs and 18% had 1 or more hospital admissions in 2020. Responders and nonresponders had similar clinical characteristics, although a higher proportion of nonresponders identified as being from 1 of the following groups: Hispanic or Latino, non-Hispanic Black, non-Hispanic multiracial, or of another race (Supplemental Table 2).

Two-thirds of respondents (n = 875) indicated vaccination intent. In the multivariable analysis (Fig 1), demographic variables had few associations with vaccination intent; however, parents of younger children (<12 years) had significantly lower adjusted odds of vaccination intent (adjusted odds ratio [95% confidence interval]: 0.26 [0.18–0.38]) compared to parents of children ≥12 years. CMC with a higher severity of illness, ie, those with ≥1 hospitalization (vs none) or >1 CCC (vs 1), had higher adjusted odds of vaccination intent (1.75 [1.09–2.81] and 1.74 [1.13–2.67], respectively).

Vaccine perceptions with the largest effect sizes on vaccination intent were “My doctor told me to get my child a COVID-19 vaccine” and “I’m concerned about my child’s side effects from the vaccine” (2.97 [1.82–4.83] and 0.18 [0.120.27], respectively). Associations between vaccine perceptions and vaccination intent can be found in Fig 1.

In this cross-sectional survey, only two-thirds of CMC parents indicated COVID-19 vaccination intent. Although this might be a higher proportion than general pediatric populations,⁴  the unique vulnerability of CMC highlights the need for further action. Our findings suggest that parental vaccination intent revolves broadly around child safety concerns and personal risk assessment. These perceptions associated with COVID-19 vaccination intent from this regional cohort represent several clinical and policy targets to promote acceptance.

First, as observed in other pediatric vaccine hesitancy studies with general populations not limited to CMC,^4,10  physician recommendation greatly correlates with acceptance. General and subspecialty pediatricians have an opportunity to listen carefully to concerns, provide trusted sources of information, and encourage vaccination. Addressing safety concerns is of paramount importance. From clinical practice, we know that concerns differ greatly from one family to another, eg, some fear fevers could precipitate metabolic crisis or seizures, or that myocarditis may complicate preexisting cardiovascular disease. Others fear complications stemming from concerns about insufficient CMC inclusion in vaccine safety and efficacy trials.

Although physicians should share evidence-informed safety messaging for all families, caregivers of CMC may have more nuanced information needs. For example, clinicians can highlight that, in the phase 2 to 3 safety and efficacy studies of the BNT162b2 vaccine (commonly referred to as the “Pfizer vaccine”) among 5- to 11-year-old children, 20% of the participating children had coexisting conditions, including conditions commonly faced by CMC.¹¹  The American Academy of Pediatrics, the Centers for Disease Control and Prevention, and the Children’s Hospitals’ Association provide additional useful resources.^12–14  Finally, because parents of children ages 5 to 12 years were the least likely to have vaccination intent (52.3%), specific attention must be directed to this population.

Limitations include unknown generalizability beyond the Midwest, survey responses underrepresenting non-White, Hispanic, or commercially insured participants, and the likelihood that COVID-19 vaccine perceptions will change with time and with authorization to younger ages. Although underrepresentation of non-White racial and ethnic groups may have affected our results, the direction of bias is unclear. For example, recent papers note differences in vaccination intent, with Non-Hispanic Asian and Hispanic populations reporting the highest intent to vaccinate; however, these differences may no longer be significant in adjusted models.^4,15 

This study is among the first to quantify vaccine intentions among CMC, noting that constructs associated with hesitancy are potentially modifiable. Pediatrician endorsement of COVID-19 vaccination and careful counseling on side effects might be promising strategies to increase uptake. Additional research on vaccine uptake for this high-risk population is needed.