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

Background
Vaccination is one of the most significant developments 
in modern science, improving the treatment and control-
ling the spread of diseases across communities. For for-
mulation scientists and immunologists, there has been 
an interest in the development of liposomal vaccines 
for their prophylactic uses in infections (of viral, bacte-
rial, fungal or parasitic origin) [
1
–
3
]. To develop safe and 
effective liposome-based vaccines, scientists should take 
into consideration several interconnected principles: (1) 
the design-dependent function of the liposomes (2) the 
characteristics of liposome-cell interactions when vac-
cine administration occurs and (3) the specific cell recep-
tor and signaling involved once liposomal vaccines are 
administered. Each of these principles will affect vac-
cine efficacy and its potential development from bench 
to bedside applications. These three principles are also 
the basis for developing excellent subunit vaccine strat-
egies, which have been of important interest for vaccine 
scientists for several years [
4
–
7
]. To comprehend how 
the potential liposomal vaccine might work in the host 
we must understand the immune responses involved in 
receptor signaling. The field of immunology plays a sig-
nificant role that will help determine the utilization of 
vaccinology to the advantage of the patient by developing 
adequate prophylactic treatment approaches.
Immunologists investigate how our bodies defend 
themselves from pathogens by determining and describ-
ing the signaling mechanisms involved. Basically, when 
infection occurs, the innate arm of the immune system 
responds through recognition of distinct molecules on or 
in pathogens termed ‘pathogen associated molecular pat-
terns (PAMPs)’. These PAMPs differ from host markers