TABLE 2.

Chitosan nanoparticle-based vaccines: physicochemical properties, immune responses, and efficacy induced by vaccines administered by intranasal route to protect against viral infectious diseases of pigs.

Vaccine carrier	Chitosan NPs based vaccine: physicochemical properties	Target pathogens	Encapsulated antigens	Route of delivery; antigen amount; number of vaccine doses	Target animal	Immune correlates and pathogen clearance	References
Chitosan NPs	Low molecular weight chitosan Size: 141 nm Zeta potential: +30.7 mV Shape: -	Swine influenza virus	Whole inactivated influenza virus	Intranasal; 107 TCID50 of the virus; 2	Pigs	Induced cross-reactive serum HI titers, cell mediated immune response, cytokine gene expression; partially reduced heterologous lung pathology and virus load in nasal passage comparable to the commercial vaccine	Renu et al., 2020a
Chitosan NPs	Low molecular weight chitosan Size: 571.7 nm Zeta potential: +1.69 mV Shape: spherical	Swine influenza virus	Whole inactivated influenza virus	Intranasal; 107 TCID50 of the virus; 2	Pigs	Enhanced mucosal secretory IgA and serum IgG antibody; reduced macroscopic and microscopic pulmonary lesions; reduced virus titers in nasal swab and BAL fluid	Dhakal et al., 2018
Chitosan and alginate NPs loaded with bee venom	—	Porcine reproductive and respiratory syndrome virus	None	Intranasal; -; 1 to 3	Pigs	Enhanced Th1-related and reduced Treg-specific immune response; increased IFN-γ secreting T cells; decreased body temperature; reduced lung lesions; lower viral load in serum and tissues	Lee et al., 2018

NPs, nanoparticles; TCID₅₀, 50% cell culture infectious dose; HI, hemagglutination inhibition; Th1, T helper type 1; IFNγ, interferon gamma; and BAL, bronchoalveolar lavage fluid.