COVID-19 Vaccination Among Hospitalized Patients at Seattle Children’s Hospital

COVID-19 vaccines are recommended for children and adolescents 5-17 years old; however, little available data have described children and adolescents who have been vaccinated against COVID-19, particularly those who are at the highest risk of complications. This study aimed to characterize hospitalized patients 5-17 years old who received a COVID-19 vaccine before hospital admission and identify the demographic, clinical, and visit factors associated with COVID-19 vaccination status at the time of hospital admission. In addition, this study aimed to describe those who received a COVID-19 vaccine during hospitalization.Electronic medical record data were used to obtain information for describing COVID-19 vaccination status before and during hospitalization among 5-17 year-old Washington State residents who were hospitalized on the medical, surgical, psychiatry and behavioral medicine, or rehabilitation unit at Seattle Children’s Hospital between October 1st, 2021 and April 15th, 2022. Multivariable logistic regression was used to estimate adjusted odds ratios (AOR) and 95% confidence intervals (CI) for associations between demographic, clinical, and visit factors and COVID-19 vaccination status at the time of hospital admission. Of the 2,004 patients included in the study, 680 (33.9%) had received at least one dose of a COVID-19 vaccine before hospital admission. Patients had lower odds of having already received a COVID-19 vaccine before hospital admission if they were 5-11 years old (vs. 16-17 years old, AOR: 0.36; CI: 0.27-0.48) or were publicly insured or uninsured (vs. privately insured, AOR: 0.48; CI: 0.38-0.61). Those who had received an influenza vaccine in the 2020-21 or 2021-22 season before admission (vs. those who did not receive an influenza vaccine in the 2020-21 or 2021-22 season before admission) had higher odds (AOR: 3.76; CI: 2.90-4.91) of having received a COVID-19 vaccine before admission. Of the 2,004 patients included in the study, only thirty-one patients (1.5%) received a COVID-19 vaccine during hospitalization. The majority of these patients had complex chronic conditions (67.7%) and were admitted to a medical unit (70.4%). This study revealed significant associations between certain demographic and clinical factors and COVID-19 vaccination status at the time of hospital admission. Low incidence of COVID-19 vaccination among inpatients during their hospital stay represents a missed opportunity to administer vaccines to high-risk children. These findings may be used to inform interventions to increase COVID-19 vaccine uptake among patients in pediatric hospital settings.