title: Chronic HIV-1 infection frequently fails to protect against superinfection.
abstract: Reports of HIV-1 superinfection (re-infection) have demonstrated that the immune response generated against one strain of HIV-1 does not always protect against other strains. However, studies to determine the incidence of HIV-1 superinfection have yielded conflicting results. Furthermore, few studies have attempted to identify superinfection cases occurring more than a year after initial infection, a time when HIV-1-specific immune responses would be most likely to have developed. We screened a cohort of high-risk Kenyan women for HIV-1 superinfection by comparing partial gag and envelope sequences over a 5-y period beginning at primary infection. Among 36 individuals, we detected seven cases of superinfection, including cases in which both viruses belonged to the same HIV-1 subtype, subtype A. In five of these cases, the superinfecting strain was detected in only one of the two genome regions examined, suggesting that recombination frequently occurs following HIV-1 superinfection. In addition, we found that superinfection occurred throughout the course of the first infection: during acute infection in two cases, between 1-2 y after infection in three cases, and as late as 5 y after infection in two cases. Our results indicate that superinfection commonly occurs after the immune response against the initial infection has had time to develop and mature. Implications from HIV-1 superinfection cases, in which natural re-exposure leads to re-infection, will need to be considered in developing strategies for eliciting protective immunity to HIV-1.
authors.affiliation: Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America.
authors.forename: Anne
authors.initials: A
authors.lastname: Piantadosi
authors.forename: Bhavna
authors.initials: B
authors.lastname: Chohan
authors.forename: Vrasha
authors.initials: V
authors.lastname: Chohan
authors.forename: R Scott
authors.initials: RS
authors.lastname: McClelland
authors.forename: Julie
authors.initials: J
authors.lastname: Overbaugh
mesh_terms: D001483:Base Sequence; D002908:Chronic Disease; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000145:classification* / Q000235:genetics / Q000276:immunology*; D006801:Humans; D015994:Incidence; D008969:Molecular Sequence Data; D010802:Phylogeny; D015163:Superinfection / Q000453:epidemiology* / Q000276:immunology*; D019562:Viral Load; D054299:env Gene Products, Human Immunodeficiency Virus / Q000235:genetics; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000235:genetics
chemical_list: D054299:env Gene Products, Human Immunodeficiency Virus; D054301:gag Gene Products, Human Immunodeficiency Virus