 The study found that N-2 hydroxy, propyl-3, trimethylammonium chytosan chloride, HTCC, a cationically modified chytosan, enhances the immune response to hepatitis E virus, HEV, recombinant polypeptid vaccine when coadministered intramuscularly. HTCC was shown to increase serum HEV specific IgG antibodies, splenocytes proliferation, and the growths of CD for plus CD8 T lymphocytes and IFN secreting T lymphocytes in peripheral blood, indicating a strong immunoenhancing effect. The study also demonstrated that HTCC is safe and effective in inducing a good antibody response and stimulating TH1, biased immune responses for HEV recombinant polypeptid vaccine. This article was authored by Wei Dao, Hai Kunjing, Ting Fu, and others.