Objective: To review the immunogenicity and safety of a hepatitis B vaccine containing the cytosine phosphoguanosine (CpG) 1018 adjuvant (HepB-CpG).
Data sources: Literature searches were performed using PubMed and Scopus with the search terms hepatitis B vaccine, HepB-CpG, CpG 1018, 1018-ISS, HBsAg-1018, HBV-ISS, and Heplisav. Other sources included the Centers for Disease Control, the Food and Drug Administration, the Advisory Committee on Immunization Practices (ACIP), and prescribing information.
Study selection and data extraction: Search limits included randomized controlled trial in humans and published in English from January 2003 to August 2020. Studies using the final formulation and dosing schedule were reviewed.
Data synthesis: Studies demonstrated that 2 doses of HepB-CpG induced significantly higher seroprotective responses with a faster onset in adults, including those in hyporesponsive populations, compared with 3 doses of alum-adjuvanted Engerix-B. Although the safety profile was comparable to that of Engerix-B, one study observed higher rates of acute myocardial infarction, herpes zoster, and death with HepB-CpG.
Relevance to patient care and clinical practice: ACIP recommends use of HepB-CpG as an option to prevent hepatitis B virus infection in adults ≥18 years old. Higher immune responses after 2 doses make it a promising option, especially in those with risk factors for hyporesponsiveness or at risk for poor adherence to vaccine series completion. Additional data are needed regarding the vaccine's safety in the general population and the persistence of its antibody response.
Conclusion: HepB-CpG has been shown to be as immunogenic as Engerix-B; however, long-term safety and persistence of immune memory has yet to be established.