Studies have shown that HIV infections cause a graded impairment of antibody response depending on the progression of disease. Clinical HIV infection ranges from asymptomatic to an acute infectious mononucleosis-like syndrome, to AIDS-related complex (ARC), often associated with generalized lymphadenopathy, oral thrush, or wasting, and AIDS. Asymptomatic HJV-infected individuals have a good antibody response to both the trivalent influenza vaccine (T cell-dependent B-cell stimulator) and the 23-valent pneumococcal vaccine (T cell-independent B-cell stimulator).
HIV-infected individuals with ARC and progressive lymphadenopathy have a blunted response to pneumococcal vaccine and a good response to tetanus toxoid (another T cell-dependent B-cell stimulator. Both the above groups of patients have T4 helper cell counts above 400 X10P/L. Therefore, despite a decrease in T4 cell number, the T cell responds appropriately to antigen and stimulates a B-cell antibody response. The B cell, however, loses some of its ability to respond appropriately to T cell-independent antigens such as the Pneumococcus antigen and gives a poorly directly antibody response (ie, the patient is more prone to infection).