Fungal vaccines: real progress from real challenges

Among viral, bacterial, and fungal diseases, the latter are the only branch of infectious diseases without a vaccine for any of their causative agents. This is at odds with a disease burden that remains unabated by conventional chemotherapy and infection control measures. Since most fungal infections occur in immunocompromised patients, the generation of tools relying on host immunity for effectiveness is a notable challenge. Nevertheless, with improved knowledge of the host-fungus relation, and the spectacular advances in genome sequencing, genetic engineering, and proteomics, strong progress in fungal vaccine research is being made. Some vaccines induce the generation of directly fungicidal antibodies; others are protective in animals carrying major risk factors for fungal infections, such as CD4+ T-cell-deficiency or neutropenia. Together with the demonstrated efficacy of various antibodies in passive vaccination approaches, there is growing confidence in the future availability of safe and efficacious immunological tools to combat deadly microbes in a weak host.