Yes,other report by Chakraborty and colleagues indicate that superinfection may be not so high. They studied fourteen HIV seroconcordant couples (ie, partners were independently infected with different HIV-1 strains) with high risk of re-exposure to the virus. Phylogenetic analyses based on pol and env global sequences obtained from more than a 100 longitudinal plasma samples over one to four years failed to detect HIV-1 superinfection in this cohort patients. They conclude that chronic HIV infection seems to confer protection against superinfection with a second HIV-1 strain. Obviously, more work needs to be done to determine what factors are responsible for superinfection in some individuals and protection in others, both at high risk of reinfection.