Codelivery of antigens and adjuvant in polymeric nanoparticles coated with native parasite membranes induces protective mucosal immunity against Giardia lamblia

Summary

This preclinical study develops a mucosal vaccine against Giardia lamblia, a protozoan that causes diarrhea and nutrient malabsorption worldwide. Existing infections are treated with antimicrobials, but resistance and failed therapy create a need for prevention. Natural infection can produce substantial protection, whereas vaccines based on individual antigens have protected experimental animals less effectively. To present a broader antigen set, the researchers collected native parasite membrane and coated it onto uniform, stable polymer nanoparticles. A mucosal adjuvant was loaded inside the same particles, ensuring that parasite antigens and immune stimulation were delivered together. The formulation was administered intranasally to mice. It induced an adaptive immune response and protected the animals against subsequent Giardia infection. The principal finding is that a multiantigenic parasite membrane and a mucosal adjuvant can be codelivered in one nanoscale construct to generate protective immunity at a relevant barrier site. This provides proof of concept for a Giardia vaccine strategy that more closely resembles the antigenic breadth of infection than a single-antigen formulation. The abstract does not specify immune correlates, degree or duration of protection, parasite strains, safety, comparator vaccines, or applicability to humans.