A number of studies with subtype B-infected individuals have determined that between 40 and 50 percent of AIDS patients can harbour viruses of the SI and, it is presumed, the X4 phenotypes.
Varios estudos con persoas infectadas polo subtipo B determinaron que entre o 40 e o 50% dos pacientes de SIDA poden ter virus de cepas indutoras de sincitios (SI) e, crese que dos fenotipos X4.