Vaccination against helminth parasite infections

Abstract

Helminth parasites infect over one fourth of the human population and are highly prevalent in livestock worldwide. In model systems, parasites are strongly immunomodulatory, but the immune system can be driven to expel them by prior vaccination. However, no vaccines are currently available for human use. Recent advances in vaccination with recombinant helminth antigens have been successful against cestode infections of livestock and new vaccines are being tested against nematode parasites of animals. Numerous vaccine antigens are being defined for a wide range of helminth parasite species, but greater understanding is needed to define the mechanisms of vaccine-induced immunity, to lay a rational platform for new vaccines and their optimal design. With human trials underway for hookworm and schistosomiasis vaccines, a greater integration between veterinary and human studies will highlight the common molecular and mechanistic pathways, and accelerate progress towards reducing the global health burden of helminth infection.

Keywords::

• echinococcosis
• filariasis
• hookworm
• schistosomiasis
• trichostrongylidiasis

Financial & competing interests disclosure

J Hewitson and R Maizels were supported by a grant from the Wellcome Trust. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Vaccine antigen selection can be clouded by the immense choice now posed by genomic analyses.

• Focus on functional antigens, for example proteases or immunomodulatory products, is more likely to bear fruit.

• Hidden antigens should be considered in addition to natural targets of antibody responses in infection.

• Helminths may promote regulatory responses through antigens or epitopes which should be modified or omitted from vaccine formulations.

• Helminth immunity is generally type 2-mediated, but better tools to drive type 2 response upon vaccination are needed.

Notes