A review of combination adjuvants for malaria vaccines: a promising approach for vaccine development

•Subunit malaria vaccines fail to induce strong and long-lasting immune responses.•Adjuvants are essential for generating stronger and protective subunit vaccines.•No single adjuvant is capable of eliciting protective immunity in a malaria vaccine.•Combination adjuvants are a potent approach to improvemalaria vaccine efficacy.•This review outlines the status of combination adjuvants in malaria subunit vaccines.