597004 Provided is a method for adjuvanting lipopolysaccharide (LPS) from a Gram-negative bacterium, according to which: (i) LPS or LPS liposomes (LPS formulated in liposomes) is (are) mixed with the lipidated human transferring receptor subunit B (lipidated TbpB) from, Neisseria meningitidis or a lipidated fragment thereof or (ii) LPS and the lipidated TbpB from N meningitidis or a lipidated fragment thereof are formulated together in liposomes or (iii) LPS is conjugated with the lipidated TbpB from N meningitidis or a lipidated fragment thereof in order to obtain a preparation which does not contain OMVs and which is capable of inducing, after administration to a mammal, an anti-LPS immune response which is improved by comparison with the anti-LPS immune response observed after administration of the corresponding preparation in which the lipidated TbpB from N meningitidis or a lipidated fragment thereof is omitted.
