A novel MF59 and CpG1018 adjuvant combination enhances the humoral and cellular immune responses against a truncated varicella-zoster viral glycoprotein E

Abstract

Vaccination is the only effective strategy for preventing herpes zoster (HZ), a disease caused by reactivation of the varicella-zoster virus (VZV). Cell-mediated immunity (CMI) plays a pivotal role in controlling VZV reactivation and is a critical factor in the efficacy of the HZ vaccine. This research introduced the preliminary utilization of truncated glycoprotein E (tgE) as the antigen in the formulation of an innovative recombinant HZ vaccine and explored the combination of tgE with several adjuvants to assess their effectiveness in eliciting robust humoral and CMI responses in C57BL/6 mice, followed by the immunogenicity validation of the optimal vaccine formulation in Sprague-Dawley (SD) rats and cynomolgus monkeys. The results demonstrated that the combination of tgE with MF59 and CpG1018, designated as tgE/MF59+CpG1018, elicited significantly stronger gE-specific humoral and cellular immune responses in C57BL/6 mice compared to any single adjuvant or other adjuvant combinations. The optimal dosages for MF59 and CpG1018 were determined to be 0.025 ml and 10 μg, respectively, for each 0.05 ml of the vaccine formulation. Notably, the increasing in the dosage of the adjuvant does not inherently correlate with a more pronounced immune response. Furthermore, the tgE/MF59+CpG1018 also elicited robust humoral and CMI responses in both SD rats and cynomolgus monkeys. These findings established the novel tgE/MF59+CpG1018 vaccine as a highly promising prophylactic candidate against HZ.