Liposomal vaccine formulations as prophylactic agents: design considerations for modern vaccines

Amoebiasis
Finally, a research paper dealing with parasitic infections 
present us the incorporation of Entamoeba histolytica 
Gal/GalNAc lectin LecA antigen in liposomal, emulsion 
and alum formulations containing synthetic TLR ago-
nists adjuvants [
59
]. E. histolytica is an anaerobic amoeba 
and is the etiological agent of amoebiasis, or diarrheal 
disease commonly transmitted through contaminated 
water and food sources [
119
]. The liposome formulation 
containing a TLR4 and TLR7/8 agonists was selected for 
further studies due to its ability to induce intestinal IgA, 
plasma IgG2a/IgG1, IFN-γ and IL-17a. A high mucosal 
IgA response hinder the ability of parasites to adhere 
to mammalian cells. The subcutaneous immunization 
regime success rate reached 55% efficacy.
Parasitic infections are common especially in underde-
veloped regions, posing a notable risk for children, adults 
and the elderly. Further studies should address the use 
of adjuvants and their immunomodulatory mechanisms 
when administered in liposomes for vaccine develop-
ment. Several studies previously discussed optimized 
certain formulations for vaccine development and we 
invite the reader to have a look at them (Table 
6
). Addi-
tionally, specific antigens should be employed to induce 
even more specific immune responses that will enhance 
the eradication of relevant parasitic diseases like leish-
maniasis and amoebiasis. Furthermore, studies should 
consider administration routes as potential factors that 
may affect the immunomodulatory responses of vaccines 
for the treatment of parasitic infections. For instance, 
toxicity of L. donovani was reduced when administered 
intravenously and differences in the immune response 
cytokine profile were detected. These cytokine profiles 
must need to be addressed, conducting studies with the 
similar liposomal formulation and administering the vac-
cines through different routes.