Overcoming original (antigenic) sin

Clin Immunol. 2001 Nov;101(2):152-7. doi: 10.1006/clim.2001.5114.


Original antigenic sin describes a phenomenon in which the antibody response elicited in an individual after a secondary viral infection reacts more strongly to the viral variant that originally infected the individual. As T helper cells play critical roles in promoting antibody responses, a similar phenomenon may hold true for T helper cell responses. This concept is particularly relevant to the development of vaccines against viruses such as human immunodeficiency virus and hepatitis C virus, in which myriad viral variants are present throughout the human population. We have compared the effects of priming the immune system with a single peptide epitope or with a cocktail of related peptides based on the epitope. Our data demonstrate that immunization with multiple peptide variants expands a more broadly reactive and durable T helper cell response than does immunization with a single peptide. This vaccine strategy may circumvent original antigenic sin.

MeSH terms

  • AIDS Vaccines / immunology*
  • Amino Acid Sequence
  • Animals
  • HIV Envelope Protein gp120 / immunology*
  • HIV-1 / immunology*
  • Immunization
  • Immunologic Memory*
  • Mice
  • Mice, Inbred BALB C
  • Molecular Sequence Data
  • T-Lymphocytes / immunology*
  • T-Lymphocytes, Helper-Inducer / immunology


  • AIDS Vaccines
  • HIV Envelope Protein gp120