A Ferritin-Based Eg95 Nanoparticle Vaccine Adjuvanted with pCpG Eliciting Robust Immune Responses Against Cystic Echinococcosis in Mice Model

Cystic echinococcosis (CE), a chronic disabling parasitic zoonosis, poses a great threat to public health and livestock production and causes huge economic losses globally. The commercial Quil-A-adjuvanted Eg95 vaccine was empirically effective for CE control; however, it is expensive and has side effects and insufficient immunity.

This study aimed to employ a novel adjuvant consisting of a delivery system and an immune potentiator and assess its adjuvanticity to Eg95 antigen, thereby developing a safe and cost-effective novel vaccine against the disease.

A ferritin-based Eg95 nanoparticle antigen was prepared and then mixed with a plasmid containing the TLR9 agonist CpG to formulate a novel nanovaccine. The safety and efficacy of the vaccine were evaluated in vitro and in vivo.

The nanovaccine induced potent and enduring Eg95-specific humoral and cellular immune responses, as well as protective immunity-associated Th1 polarization supported by the higher ratios of IgG2a/IgG1 and IFN-γ/IL-4. Meanwhile, this nanovaccines exhibited favorable safety and economic profiles.

Our data demonstrated that the ferritin-CpG hybrid is a promising combination adjuvant to upgrade the traditional Quil-A and this combination adjuvant-based nanovaccine presents good potential as an alternative to the commercial one for practical CE control.