Immunity and protection by live attenuated HIV/SIV vaccines.
Live attenuated virus vaccines have shown the greatest potential to protect against simian immunodeficiency virus (SIV) infection, a model for human immunodeficiency virus (HIV). Immunity against the vaccine virus is thought to mediate protection. However, it is shown computationally that the opposite might be true. According to the model, the initial growth of the challenge strain, its peak load, and its potential to be pathogenic is higher if immunity against the vaccine virus is stronger. This is because the initial growth of the challenge strain is mainly determined by virus competition rather than immune suppression. The stronger the immunity against the vaccine strain, the weaker its competitive ability relative to the challenge strain, and the lower the level of protection. If the vaccine virus does protect the host against a challenge, it is because the competitive interactions between the viruses inhibit the initial growth of the challenge strain. According to these arguments, an inverse correlation between the level of attenuation and the level of protection is expected, and this has indeed been observed in experimental data.
Wodarz
Dominik
D
Department of Ecology and Evolution, 321 Steinhaus Hall, University of California, Irvine CA 92697, USA. dwodarz@uci.edu
D016915:AIDS Vaccines / Q000276:immunology*; D000818:Animals; D006678:HIV / Q000254:growth & development* / Q000276:immunology; D015658:HIV Infections / Q000517:prevention & control* / Q000821:virology; D006801:Humans; D008962:Models, Theoretical; D018449:SAIDS Vaccines / Q000276:immunology*; D016097:Simian Acquired Immunodeficiency Syndrome / Q000517:prevention & control* / Q000821:virology; D015302:Simian Immunodeficiency Virus / Q000254:growth & development* / Q000276:immunology; D014613:Vaccines, Attenuated / Q000276:immunology
D016915:AIDS Vaccines; D018449:SAIDS Vaccines; D014613:Vaccines, Attenuated