Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Prior studies demonstrated that immunization of macaques with simian immunodeficiency virus (SIV) Gag-Pol and Env recombinants of the attenuated poxvirus modified vaccinia virus Ankara (MVA) provided protection from high levels of viremia and AIDS following challenge with a pathogenic strain of SIV (V. M. Hirsch et al., J. Virol. 70:3741-3752, 1996). This MVA-SIV recombinant expressed relatively low levels of the Gag-Pol portion of the vaccine. To optimize protection, second-generation recombinant MVAs that expressed high levels of either Gag-Pol (MVA-gag-pol) or Env (MVA-env), alone or in combination (MVA-gag-pol-env), were generated. A cohort of 24 macaques was immunized with recombinant or nonrecombinant MVA (four groups of six animals) and was challenged with 50 times the dose at which 50% of macaques are infected with uncloned pathogenic SIVsmE660. Although all animals became infected postchallenge, plasma viremia was significantly reduced in animals that received the MVA-SIV recombinant vaccines as compared with animals that received nonrecombinant MVA (P = 0.0011 by repeated-measures analysis of variance). The differences in the degree of virus suppression achieved by the three MVA-SIV vaccines were not significant. Most importantly, the reduction in levels of viremia resulted in a significant increase in median (P < 0.05 by Student's t test) and cumulative (P = 0.010 by log rank test) survival. These results suggest that recombinant MVA has considerable potential as a vaccine vector for human AIDS.

Original publication




Journal article


Journal of virology

Publication Date





2740 - 2751


Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, Rockville, Maryland 20852, USA.


CD4-Positive T-Lymphocytes, Cell Line, Animals, Macaca mulatta, Vaccinia virus, Simian Acquired Immunodeficiency Syndrome, Membrane Glycoproteins, Gene Products, env, Gene Products, gag, Fusion Proteins, gag-pol, Vaccines, DNA, HIV Envelope Protein gp120, Viral Envelope Proteins, Viral Matrix Proteins, SAIDS Vaccines, Antibodies, Viral, Antigens, Viral, CD4 Lymphocyte Count, Viral Load, Gene Expression, Recombination, Genetic, Genetic Vectors, Simian immunodeficiency virus, Chlorocebus aethiops