Efficacy of Hepatitis B Vaccination with a Novel Immunostimulatory Sequence Adjuvant (Heplisav-B) in Patients With Inflammatory Bowel Disease

Efficacy of Vaccination and Revaccination Against Hepatitis B Virus Using 2 Different Strategies in Patients With Inflammatory Bowel Disease

BACKGROUND

Patients with inflammatory bowel disease (IBD) exhibit an increased risk for acquiring hepatitis B virus (HBV), thus they should be vaccinated preferably, if not already infected or immunized. We assessed the efficacy of HBV vaccination in IBD patients and impact of different factors on the immune response. We also evaluated the success rate of 2 different revaccination strategies in the nonresponders.

METHODS

This was a retrospective observational cohort study carried out in 5 tertiary centers. All patients were tested for hepatitis B surface antigen, antibodies against hepatitis B surface antigen (anti-HBs), and antibodies against hepatitis B core antigen. Patients tested negative and underwent the standard schedule with 20 µg at 0, 1, and 6 months. Nonresponders (anti-HBs <10 IU/L) were offered a revaccination scheme with either 3 doses of 40 µg at 0, 1, and 6 months or an accelerated scheme with 20 µg at 0, 1, and 2 months.

RESULTS

A total of 409 patients were included, and 273 (66.7%) of those (females: 49.5%; Crohn's disease [CD]: 56.7%) responded to baseline vaccination. A total of 189 (69.2%) of 273 (females: 48.1%; CD: 60.3%) developed anti-HBs >100 IU/L. Body mass index <30 kg/m2 (P = .017) was positively associated, while diagnosis of CD (P = .013), extensive UC (P <.0001), extraintestinal manifestations (P = .001), and treatment with immunomodulators/anti-tumor necrosis factor (P < .00) negatively affected the response. Revaccination was offered to 103 patients, and 58.3% of them achieved anti-HBs >10 IU/L. Both revaccination strategies were equally effective.

CONCLUSIONS

IBD patients demonstrate lower response to HBV vaccination compared with the general population. Age, body mass index, type, disease activity, and immunosuppression negatively affect the response. Half of nonresponders may benefit from an enhanced revaccination attempt.

Utility of a Third Heplisav-B Dose in Patients With Inflammatory Bowel Disease Without Immunity After 2-Dose Heplisav-B Vaccination

INTRODUCTION

Hepatitis B virus (HBV) vaccination is recommended in patients with inflammatory bowel disease (IBD). Although the 2-dose Heplisav-B vaccine has proven effective, more than 20% of patients with IBD do not seroconvert. We prospectively evaluated the effectiveness of a third Heplisav-B dose in patients with IBD lacking HBV immunity despite 2-dose vaccination.

METHODS

Adults with IBD who had received 2-dose Heplisav-B vaccination between 2018 and 2023 were identified. Seroconversion was defined as hepatitis B surface antibody (HBsAb) ≥ 10 IU/L measured at ≥4 weeks after vaccination. Patients who did not seroconvert were prospectively offered a third Heplisav-B dose, followed by repeat HBsAb measurement. Demographic, clinical, medication, and vaccination data were compared between those who did and did not seroconvert.

RESULTS

Of 192 patients identified, 71.9% (138/192) seroconverted after 2-dose Heplisav-B vaccination. The 54 patients (28.1%) who did not seroconvert were more likely to be male, have diabetes, chronic kidney disease, or elevated Charlson Comorbidity Index. Of the 54 patients, 30 (55.6%) elected to receive a third Heplisav-B dose, with 56.7% (17/30) achieving seroconversion (median HBsAb titer 376 IU/L, IQR 47-1,000 IU/L) despite a median intervaccination time of 416 days (IQR 90.8-667.8). No differences were noted between patients who did vs did not seroconvert after third-dose vaccination.

DISCUSSION

In patients with IBD lacking HBV immunity despite 2-dose Heplisav-B vaccination, administration of a third dose resulted in a 56.7% seroconversion rate. Our results suggest that administration of an additional Heplisav-B dose may be an effective strategy in patients lacking immunity despite primary 2-dose vaccination.

Biodegradable scaffolds for enhancing vaccine delivery

Sustained release of vaccine components is a potential method to boost efficacy compared with traditional bolus injection. Here, we show that a biodegradable hyaluronic acid (HA)-scaffold, termed HA cryogel, mediates sustained antigen and adjuvant release in vivo leading to a durable immune response. Delivery from subcutaneously injected HA cryogels was assessed and a formulation which enhanced the immune response while minimizing the inflammation associated with the foreign body response was identified, termed CpG-OVA-HAC2. Dose escalation studies with CpG-OVA-HAC2 demonstrated that both the antibody and T cell responses were dose-dependent and influenced by the competency of neutrophils to perform oxidative burst. In immunodeficient post-hematopoietic stem cell transplanted mice, immunization with CpG-OVA-HAC2 elicited a strong antibody response, three orders of magnitude higher than dose-matched bolus injection. In a melanoma model, CpG-OVA-HAC2 induced dose-responsive prophylactic protection, slowing the tumor growth rate and enhancing overall survival. Upon rechallenge, none of the mice developed new tumors suggesting the development of robust immunological memory and long-lasting protection against repeat infections. CpG-OVA-HAC2 also enhanced survival in mice with established tumors. The results from this work support the potential for CpG-OVA-HAC2 to enhance vaccine delivery.