Abstract: The use of non-toxic muramyl peptides, particularly Murabutide and Murametide, to prepare drugs for inhibiting HIV replication in humans is disclosed. Said muramyl peptides are capable of up to 100% inhibition of retroviral replication in primary host monocyte cultures.

Abstract: Pharmaceutical compositions containing Muramyl dipeptide derivatives and conjugates or Muramyl dipeptide derivatives and conjugates combined with nucleoside derivatives which induce hematopoietic stem cell stimulation and mobilization into the circulating blood system. Methods to induce hematopoietic stem stimulation and mobilization, as well as methods to decrease myelotoxic effects using these pharmaceutical compositions.

Abstract: Vaccines, composed of antigens absorbed on alum or formulated in an alum-containing composition, have enhanced immunogenicity over existing vaccines. The vaccines of the invention are characterized by their combination with 2-120 .mu.g per kg or 0.1 to 6 mg by dose, preferentially 6-60 .mu.g per kg or 0.3 to 3 mg per dose, of a hydrosoluble muramyl peptide.

Abstract: A therapeutical composition for use in humans, comprising a combination of at least one natural or recombinant and preferably human cytokine with at least one muramyl peptide selected from those which, when administered in vivo together with an interferon, also induce an increased in vivo production of an interleukin-1 receptor antagonist IL-1 RA, but preferably do not induce any increase in TNF, IL-8 and IL-1 cytokines. Said composition is useful for antiviral and antitumoral therapies and/or for promoting restoration of the haematopoietic system, particularly in individuals with a weakened immune system.