[HIV superinfection: clinical and biological implications].
The recognition of HIV-1 particles including recombinant virus sequences suggests that a single individual has been infected with more than one HIV subtype. This circumstance may result from superinfection or coinfection. In the first case, the new infection occurs in subjects already carrying HIV-1, whereas coinfection refers to a concomitant exposure to diverse HIV-1 variants. The demonstration of superinfection represents an indirect evidence against protective immunity for HIV-1 and, therefore, against the success of vaccines.