We studied the feasibility of using halloysite clay nanotubes (HNTs) and carboxyl-functionalised multi-walled
carbon nanotubes (COOH-MWCNTs) as antigen carriers to improve immune responses against a recombinant
LipL32 protein (rLipL32). Immunisation using the HNTs or COOH-MWCNTs significantly increased the rLipL32-
specific IgG antibody titres (p < 0.05) of Golden Syrian hamsters. None of the vaccines tested conferred protection
against a challenge using a virulent Leptospira interrogans
strain. These results demonstrated that nanotubes can
be used as antigen carriers for delivery in hosts and the induction of a humoral immune response against purified
leptospiral antigens used in subunit vaccine preparations.