Needle-free, spirulina-produced Plasmodium falciparum circumsporozoite vaccination provides sterile protection against pre-erythrocytic malaria in mice

Abstract

Antibodies against the Plasmodium falciparum circumsporozoite protein (PfCSP) can block hepatocyte infection by sporozoites and protect against malaria. Needle-free vaccination strategies are desirable, yet most PfCSP-targeted vaccines like RTS,S require needle-based administration. Here, we evaluated the edible algae, Arthrospira platensis (commonly called ‘spirulina’) as a malaria vaccine platform. Spirulina were genetically engineered to express virus-like particles (VLPs) consisting of the woodchuck hepatitis B core capsid protein (WHcAg) displaying a (NANP)15 PfCSP antigen on its surface. PfCSP-spirulina administered to mice intranasally followed by oral PfCSP-spirulina boosters resulted in a strong, systemic anti-PfCSP immune response that was protective against subcutaneous challenge with PfCSP-expressing P. yoelii. Unlike male mice, female mice did not require Montanide adjuvant to reach high antibody titers or protection. The successful use of spirulina as a vaccine delivery system warrants further development of spirulina-based vaccines as a useful tool in addressing malaria and other diseases of global health importance.

A Systematic Review on Malaria and Tuberculosis (TB) Vaccine Challenges in Sub-Saharan African Clinical Trials

“…The mucosal MVA85A immunization in the United Kingdom induced strong immunogenicity, which has not been observed in South Africa through traditional routes (70). Even though the natural route to malaria infection does not involve mucosal surfaces, mucosal immunization with malaria-inducing antibodies protects mice (71). In addition to the immunological point of view, mucosal routes may be more economical than parenteral routes because they do not require trained personnel and hence are appropriate in resourcelimited sub-Saharan Africa.…”

Edible microalgae: potential candidate for developing edible vaccines

“…Unlike plants, algal biomass accumulation is extremely rapid, and the whole biomass can be utilized for vaccine production. Moreover, they are resistant to animal pathogens and the expression of heterologous proteins in microalgae is 10-to 100-fold higher than that of plant-based vaccines (Saveria et al 2022). Notably, C.reinhardtii contains only one chloroplast that aids in the stability of specific antigens in their cell line (Sahoo et al 2020).…”

COVID-19 Vaccines for Optimizing Immunity in the Upper Respiratory Tract

“…The finding of IgA antibodies to RBD in the nasal cavity, bronchi, and gastrointestinal tract of mice after intranasal immunization with RBD displayed on the surface of live Lactobacillus plantarum illustrates the potential of this platform for developing a nasal COVID-19 vaccine [54]. A related approach used the edible alga Arthrospira platensis, expressing a protective protein antigen from a malaria parasite, administered intranasally and orally, to induce systemic antibodies that protected against a challenge malaria infection in mice [55]. Although mucosal antibodies were not measured in this study, they are likely to have been produced by the oral immunization protocol [55].…”

“…A related approach used the edible alga Arthrospira platensis, expressing a protective protein antigen from a malaria parasite, administered intranasally and orally, to induce systemic antibodies that protected against a challenge malaria infection in mice [55]. Although mucosal antibodies were not measured in this study, they are likely to have been produced by the oral immunization protocol [55]. Immunization of hamsters by oral gavage with adenovirus-5 expressing S in appropriate enteric-coated pills generated S-specific IgG antibodies in blood as well S-specific IgA antibodies in the nose and oropharynx, demonstrating the potential for oral vaccination against COVID-19 [56].…”