Infection by human papillomavirus (HPV) is the most common sexually transmitted disease and the major cause of anogenital cancers. Prevention against anogenital cancers can be afforded by vaccination with currently licensed HPV vaccines. However, implementation of HPV vaccination worldwide is still a challenge due to vaccine-related costs and logistic requirements. To address these issues, the scientists have established a novel vaccine concept, PANHPVAX, incorporating cross-neutralization epitopes displayed on the surface of a thermostable scaffold. An additional protein domain promotes self-assembly of the whole antigen into a nanoparticle form for enhanced immunogenicity. They have initiated a clinical phase I trial of this antigen formulated with cyclic di-AMP as adjuvant. Both the adjuvant and the antigen are first-in-human immunogenic compounds; therefore, trial design involves a dose escalation strategy for both the antigen and the adjuvant. This project extends the PANHPVAX study for an additional group of participants to receive a vaccine formulated with an elevated dose of the adjuvant cyclic di-AMP. The scientists expect significantly increased immunogenicity of the vaccine due to this measure.