Immunological effect of subunit influenza vaccine entrapped by liposomes.
OBJECTIVE
To elevate the immunological effect of subunit influenza vaccine in infants and aged people (over 60) using liposomal adjuvant in the context of its relatively low immunity and to investigate the relation between vaccine antigens and liposomal characteristics.


METHODS
Several formulations of liposomal subunit influenza vaccine were prepared. Their relevant characteristics were investigated to optimize the preparation method. Antisera obtained from immunizinged mice were used to evaluate the antibody titers of various samples by HI and ELISA.


RESULTS
Liposomal trivalent influenza vaccine prepared by film evaporation in combinedation with freeze-drying significantly increased its immunological effect in SPF Balb/c mice. Liposomal vaccine stimulated the antibody titer of H3N2, H1N1, and B much stronger than conventional influenza vaccine. As a result, liposomal vaccine (mean size: 4.5-5.5 microm, entrapment efficiency: 30%-40%) significantly increased the immunological effect of subunit influenza vaccine.


CONCLUSIONS
The immune effect of liposomal vaccine depends on different antigens, and enhanced immunity is not positively correlated with the mean size of liposome or its entrapped efficiency.
Zhang
Shui-Hua
SH
College of Life Sciences and Technology, Shanghai Jiao Tong University, Shanghai 200240, China. ashui10@126.com
Liang
Jia-Xu
JX
Dai
Shu-Yan
SY
Qiu
Xiao-Lin
XL
Yia
Yan-Rong
YR
Pan
Yun
Y
D000818:Animals; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology; D009981:Influenza B virus / Q000276:immunology; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D008081:Liposomes; D051379:Mice; D008807:Mice, Inbred BALB C; D009976:Orthomyxoviridae Infections / Q000517:prevention & control*; D013047:Specific Pathogen-Free Organisms; D022223:Vaccines, Subunit / Q000008:administration & dosage / Q000276:immunology
D007252:Influenza Vaccines; D008081:Liposomes; D022223:Vaccines, Subunit