Humoral and cellular immunity induced by antigens adjuvanted with colloidal iron hydroxide

The immunopotentiating activities of colloidal iron hydroxide, a novel, exp erimental mineral adjuvant, and of aluminium hydroxide, the licensed adjuva nt for human vaccines, were compared. Our studies revealed that colloidal i ron hydroxide and aluminium hydroxide behaved comparably with respect to su pporting induction of an antibody response to tetanus toroid. Furthermore, mice immunized with both, the experimental Vaccine (tick-borne encephalitis Virus (TBEV) antigen adsorbed to colloidal iron hydroxide) or with a comme rcially available TBEV vaccine (adjuvanted with aluminium hydroxide), devel oped long-lasting antibody responses which protected the animals from TBEV infection even one year after vaccination. The use of colloidal iron hydrox ide as adjuvant had the additional advantage to reproducibly support induct ion of HIV-1 envelope-specific cytotoxic T lymphocytes (CTL), when used as adjuvant for a HIV-1 env-carrying recombinant fowlpox virus and being appli ed via the subcutaneous route. Aluminium hydroxide was much less active in this respect. Non-adjuvanted recombinant fowlpox elicited CTLs only when gi ven intravenously or intraperitoneally, vaccination routes considered not t o be suitable for routine use in humans. Further studies to evaluate the us e of colloidal iron as possible alternative and/or supplement for routinely used mineral adjuvants may therefore be warranted. (C) 1999 Elsevier Scien ce Ltd. All rights reserved.