Metazoan Parasite Vaccines: Present Status and Future Prospects

Abstract

Eukaryotic parasites and pathogens continue to cause some of the most detrimental and difficult to treat diseases (or disease states) in both humans and animals, while also continuously expanding into non-endemic countries. Combined with the ever growing number of reports on drug-resistance and the lack of effective treatment programs for many metazoan diseases, the impact that these organisms will have on quality of life remain a global challenge. Vaccination as an effective prophylactic treatment has been demonstrated for well over 200 years for bacterial and viral diseases. From the earliest variolation procedures to the cutting edge technologies employed today, many protective preparations have been successfully developed for use in both medical and veterinary applications. In spite of the successes of these applications in the discovery of subunit vaccines against prokaryotic pathogens, not many targets have been successfully developed into vaccines directed against metazoan parasites. With the current increase in -omics technologies and metadata for eukaryotic parasites, target discovery for vaccine development can be expedited. However, a good understanding of the host/vector/pathogen interface is needed to understand the underlying biological, biochemical and immunological components that will confer a protective response in the host animal. Therefore, systems biology is rapidly coming of age in the pursuit of effective parasite vaccines. Despite the difficulties, a number of approaches have been developed and applied to parasitic helminths and arthropods. This review will focus on key aspects of vaccine development that require attention in the battle against these metazoan parasites, as well as successes in the field of vaccine development for helminthiases and ectoparasites. Lastly, we propose future direction of applying successes in pursuit of next generation vaccines.

Prevention not cure: a review of methods to avoid sea lice infestations in salmon aquaculture

“…While there are no in‐principle barriers, the development of vaccines for ectoparasites is technically challenging; despite the identification of numerous vaccine targets in a range of ectoparasites, the cattle tick ( Rhipicephalus microplus ) remains the only ectoparasite with a highly effective vaccine (Stutzer et al . 2018).…”

Soil-Transmitted Helminth Vaccines: Are We Getting Closer?

“…The epitopes were identified from secreted, and surface-exposed proteins and any protein with any degree of homology to humans or mice were excluded to eliminate potential autoimmune reactions. Most of the identified vaccine antigens were stage-specific and had essential functions in the parasite biological process, associated with host-parasite interaction, parasite metabolism, development and fecundity ( 80 ).…”

Use of Veterinary Vaccines for Livestock as a Strategy to Control Foodborne Parasitic Diseases

“…In fact, only few veterinary vaccines against these parasites are commercially available to be used in livestock, whereas there is none licensed for humans. A possible explanation for the scarce progress on vaccine development against foodborne parasites, could be due to scientific obstacles, such as the complexity and diversity of foodborne parasites and a poor understanding of the host/pathogen interactions (Hewitson and Maizels, 2014;Stutzer et al, 2018;Sander et al, 2019). These obstacles severely limit the objective selection of the elements to be considered in vaccine development, including the choice of the target species, the vaccine approach, the selection of antigen/s, the immune response to be targeted, the addition of adjuvants and the route of vaccination (Chambers et al, 2016).…”