Preventing Hepatitis B Virus Infection Among U.S. Military Personnel: Potential Impact of a 2-Dose Versus 3-Dose Vaccine on Medical Readiness

INTRODUCTION: Hepatitis B, a major public health issue worldwide, has been associated with serious clinical outcomes. Military personnel are at particular risk for hepatitis B, such that hepatitis B vaccination is part of the accession process for new recruits. Although lost time costs and medical cost avoidance have been used by the U.S. Military to guide their decision-making protocols, this has not been applied to hepatitis B vaccination costs. Herein, a decision-analytic model is used to compare the effective vaccine protection rates and vaccine and operational costs of 2-dose versus 3-dose hepatitis B vaccine regimens in a population of recruits from the U.S. Marine Corps Recruit Depot, Parris Island. METHODS: A decision-analytic model was developed to assess the expected levels of adherence, seroprotection, and vaccination and operational costs of a cohort of recruits vaccinated with either a 2-dose (HepB-CpG) vaccine for those eligible (scenario 1) or a 3-dose (HepB-Alum) vaccine (scenario 2). De-identified data from 23,004 recruits at the Marine Corps Recruit Depot, Parris Island, in 2018 and 2019 were used to provide real-world data on age distribution and vaccination status. Other inputs included published data on adherence for hepatitis B vaccines and seroprotection rates for HepB-CpG and HepB-Alum in relation to the number of doses received. Costs included direct medical costs of the hepatitis B vaccination and operational costs such as missed training time. RESULTS: After receipt of two vaccine doses, 92% of recruits in scenario 1 (HepB-CpG group) were expected to be protected against hepatitis B within 1 month of receiving the second dose, compared with 24% of recruits in scenario 2 (HepB-Alum group), leaving 76% of Marine recruits unprotected if using HepB-Alum during the intervening 5-month period between doses 2 and 3. Over the study period, HepB-CpG was estimated to provide cost savings of $744,509 (17.3% cost reduction) compared with HepB-Alum, with the cost of missed training time being the most influential driver of the cost difference between the two vaccination schedules. CONCLUSIONS: Findings from this model suggest that vaccination with the 2-dose HepB-CpG vaccine may provide earlier and higher protection against hepatitis B compared with the 3-dose vaccine (HepB-Alum). A 2-dose vaccination strategy incorporated as part of individual medical readiness has the potential to not only increase protection but also confer economic savings among military recruits at risk for hepatitis B infection.