Table 1.

Advantages and disadvantages of Mother-to-Child HIV Transmission (MTCT) as a model to study protective immunity to HIV

Advantages	Disadvantages
Transmission dyad easily identified and in a stable relationship	Use of antiretrovirals markedly reduces transmission rates and transmission during prophylaxis may not represent
Period of risk exposure relatively easily quantified and susceptibility can be studied before transmission event in the case of breast milk transmission	Factors that protect infants may not be relevant to other modes of transmission particularly since infection usually occurs in presence of maternal antibody
Exposure occurs in a consistent and predictable manner	Genetic relatedness between mother and infant may limit the generalizability of certain immune responses
Relatively little social stigma associated with risk behaviors and other predisposing factors inflammatory states (e.g. infection, mastitis)