T cell memory in malaria

The observation that individuals living in malaria endemic areas fail to develop sterilizing immunity to malaria infection has led to the assumption that malaria-specific immune responses are sub-optimal. Recently, T cell receptor (TCR) transgenic mice specific for the sporozoite and blood stages of the malaria parasite have been developed. Studies using these models have found that, unexpectedly, T cell memory in malaria is not noticeably defective. However, if T cell memory is ‘normal’ why are people not better protected? We suggest this is because protective immunity and T cell memory do not always correlate; moreover, T cells alone may simply not be able to provide the type of antibody-mediated sterilizing immunity induced by traditional vaccines.