There is a continued need to develop better vaccines or alternative immune-stimulating therapies. Three recent studies focus on new strategies for boosting host immunity. In the setting of cancer, although potential target antigens are known, there is a requirement for a delivery strategy that enables antigen persistence and presentation in an inflammatory context. To achieve this, Junqueira et al. infected mice with Trypanosoma cruzi parasites that were engineered to express a testicular cancer-associated antigen. Importantly, infection with these parasites induced CD8+ T cells that protected mice from cancer in a prophylactic model and delayed tumour progression in a therapeutic model. The study by Avci et al. suggests that, in order to develop more effective vaccines against encapsulated bacteria, we should reconsider the dogma that only the peptide component of a glycoconjugate is presented on MHC molecules to T cells. The authors found that in mice infected with group B Streptococcus (GBS), antigen-presenting cells stimulate carbohydrate-specific CD4+ T cells. Notably, a vaccine constructed to maximize the presentation of GBS-derived carbohydrates to T cells was more effective than a traditional vaccine containing glycoconjugate components in inducing immunity to GBS. Finally, Balazs et al. describe an alternative approach to vaccination — vectored immunoprophylaxis. They used an adeno-associated virus vector encoding a full-length, HIV-specific neutralizing antibody to induce the production of these antibodies by mouse muscle tissue. Remarkably, in humanized mice, a single intramuscular injection of the vector induced the life-long production of HIV-specific neutralizing antibodies and fully protected these animals from HIV infection.