Hepatitis B Birth Dose Vaccination among Military Health System Beneficiaries

• Main Author: Deerin, Jessica Fung
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01.01.2021
• Subjects: Epidemiology; Health care management; Public health; Virology
• ISBN: 9798505546802

Background: The universal hepatitis B (HepB) birth dose provides a critical safeguard and prevents infection among infants born to hepatitis B surface antigen (HBsAg)-positive mothers not identified prenatally. The vaccine’s efficacy in preventing perinatal transmission decreases as the time period between birth and first dose increases. As a result of hospital implementation of the 2005 Advisory Committee on Immunization Practices (ACIP) recommendation, the HepB birth dose (defined as administered within 3 days of birth during this time period) coverage rate has increased from 50.1% among children born from 2003–2005 to 76.3% among children born from 2016–2017, but the rate is still below the Healthy People 2020 goal of 85%. An increase in vaccine hesitancy has emerged in recent years and may impact vaccine uptake and completion. We conducted three analyses to identify characteristics associated with non-receipt and refusal or delay of the HepB birth dose and to identify the impact of birth dose delay on timeliness of completion of the HepB vaccination series in the Military Health System (MHS), the global health system for the U.S. Department of Defense. Methods: For each analysis, we used linked mother-infant inpatient delivery claims data from the MHS from 2014 to 2018. The infant inpatient records were linked to outpatient records to identify delay or refusal of receipt of the HepB birth dose and to identify completion of the HepB vaccination series. We used generalized linear mixed effects models with a logit link to assess the association between individual and systemic level characteristics with non-receipt of the birth dose, where hospital and provider were random effects and individual characteristics were fixed effects. In order to assess first-time mothers’ decision-making on the HepB birth dose and the change in decision-making with subsequent children, we used a logistic regression model. In order to assess the association between delay of HepB birth dose and delayed timeliness of completion of the vaccination series, we used a multilevel Cox regression model to estimate the hazard ratio of timely completion of the HepB vaccination series. Results: HepB birth dose vaccination coverage increased from 79.6% in 2014 to 88.1% in 2018 (p < .0001). Refusal rates also increased from 3.7% in 2014 to 4.5% in 2018 (p < .0001). The percentage of patients with missing diagnosis codes for vaccine refusal or vaccination decreased from 16.7% in 2014 to 7.4% in 2018. Factors associated with non-receipt of the birth dose included earlier year of birth, white maternal race, higher maternal age, higher birth order, and higher number of infant length of stay in hospital (defined as the number of days the infant stayed in hospital prior to discharge). Among all first-time mothers who delivered at least two children during the study period, 96% of mothers made the same vaccination decision for both children, with 94% of mothers accepting the HepB birth dose for both children. When mothers decided to delay the first HepB vaccine > 3 days or refuse any HepB vaccine for the first 18 months of life for the firstborn child, there was a higher odds of the mother delaying (aOR = 46.2 (95% CI: 27.1, 78.9)) or refusing (aOR = 176.2 (95% CI: 68.0, 456.5)) the first HepB vaccine for the subsequent child compared to among those accepting the HepB birth dose. Among all children who received a HepB vaccine during the study period (N = 95,153), 97% of children received the HepB birth dose, 57.9% of children completed the HepB vaccine series by 7 months (age-appropriate) and 69.1% of children completed the series by 19 months (up-to-date). Of the 92,744 children who received the birth dose, 58% completed the series by 7 months of age. Of the 2,409 children who delayed the first HepB vaccine > 3 days of life, 43% completed the series by 7 months of age. Children who delayed the first HepB vaccine > 3 days were 40% less likely to have timely completion of the HepB vaccination series compared to those who received the birth dose (aHR = 0.60, 95% CI: 0.57, 0.63). Conclusion: In this analysis utilizing administrative claims data from the MHS, we found that vaccination coverage for HepB birth dose is high in the MHS and increased over time; concurrently, refusal rates also increased over time. Utilization of administrative claims also has the benefit of differentiating reasons for non-receipt of the birth dose over time. Military hospitals and providers must utilize evidence-based strategies to address vaccine hesitancy among parents making decisions on the first vaccine a child receives in life. This study provides evidence that parents are likely to make the same vaccination decision for subsequent children. Therefore, public health intervention should focus on mothers who delayed or refused the first HepB vaccine for the firstborn child to improve HepB birth dose vaccine uptake for subsequent children. Although birth dose rates are high, military beneficiaries have lower vaccination coverage at 19 months of age compared to the U.S. general population. Delay of the first dose of the HepB vaccine was associated with delayed completion of the HepB vaccination series. Medical providers should continue to encourage parents to provide the HepB birth dose according to ACIP recommendations.