Abstract: Peptide fragments of the p17 gag protein of HIV-1 from Clade C of from about 30 to about 50 amino acids, including the region extending from position 75 to position 129, raise antibodies recognizing other subtypes, including Clade A, Clade B, Clade E as well as peptides of non-coextensive but overlapping portions of the p17 gag protein. DNA sequences can be used to encode for the peptides of interest.

Abstract: Peptide fragments of the p17 gag protein of HIV-1 from Clade C of from about 30 to about 50 amino acids, including the region extending from position 75 to position 129, raise antibodies recognizing other subtypes, including Clade A, Clade B, Clade E as well as peptides of non-coextensive but overlapping portions of the p17 gag protein. DNA sequences can be used to encode for the peptides of interest.

Abstract: A peptide of up to about 40 amino acids including the core sequence inclusive of amino acids at positions 92-109 of the p17 gag core protein of HIV-1, such as, Ile-Y.sub.1 -Y.sub.2 -Lys-Asp-Thr-Lys-Glu-Ala-Leu-Y.sub.3 -Lys-Ile-Glu-Glu-Glu-Gln-AsnwhereinY.sub.1 is Asp or Glu,Y.sub.2 is Val or Ile, andY.sub.3 is Glu or Asp,is effective in inhibiting replication of the HIV virus and provides the basis for a vaccine for treatment or prevention of AIDS.

Abstract: Vaccines effective in the inhibition of infection caused by the family of retroviruses, HTLV-III, Human T-Cell Leukemia Virus, LAV, Lymphadenopathy-associated virus, ARV-2, AIDS-Related Virus, (AIDS and AIDS-Related Complex) have been developed from an antisera prepared against thymosin .alpha..sub.1 (T.alpha..sub.1), a thymic hormone, as well as from antisera to synthetic peptide fragments of T.alpha..sub.1 and antisera to synthetic peptide fragments inclusive of amino acid positions 92-109 of the p17 gag core protein of HTLV-III, LAV and ARV-2. In this 18 amino acid primary sequence there is a 44 to 50% homology between the gag protein and T.alpha..sub.1. Immunoglobulin (IgG)-enriched preparations of the T.alpha..sub.1 antisera have enhanced activity in blocking vital replication. A diagnostic test capable of directly detecting the presence of HTLV-III, LAV, ARV-2 and related retroviruses associated with AIDS and ARC is also described.

Abstract: Vaccines effective in the inhibition of infection caused by the family of retroviruses, HTLV-III, Human T-Cell Leukemia Virus, LAV, Lymphadenopathy-associated virus, ARV-2, AIDS-Related Virus, (AIDS and AIDS-Related Complex) have been developed from an antisera prepared against thymosin .alpha..sub.1 (T.alpha..sub.1), a thymic hormone, as well as from antisera to synthetic peptide fragments of T.alpha..sub.1 and antisera to synthetic peptide inclusive of amino acid positions 92-109 of the p17 gag core protein of HTLV-III, LAV and ARV-2. In this 18 amino acid primary sequence that is a 44 to 50% homology between the gag protein and T.alpha..sub.1. Immunoglobulin (IgG)- enriched preparations of the T.alpha..sub.1 antisera have enhanced activity in blocking viral replication. A diagnostic test capable of directly detecting the presence of HTLV-III, LAV, ARV-2 and related retroviruses associated with AIDS and ARC is also described.