Impaired cellular immune response to tetanus toxoid but not to cytomegalovirus in effectively HAART-treated HIV-infected children.

Despite of highly active antiretroviral therapy, the response to vaccines in HIV-infected children is poor and short-lived, probably due to a defect in cellular immune responses. We compared the cellular immune response (assessed in terms of IFN-γ production) to tetanus toxoid and to cytomegalovirus in a series of 13 HIV-perinatally-infected children and adolescents with optimal immunovirological response to first line antiretroviral therapy, implemented during chronic infection. A stronger cellular response to cytomegalovirus (11 out of 13 patients) was observed, as compared to tetanus toxoid (1 out of 13; p=0.003). These results suggest that the repeated exposition to CMV, as opposed to the past exposition to TT, is able to maintain an effective antigen-specific immune response in stable HIV-infected pediatric patients and strengthen current recommendations on immunization practices in these children.