Conflicting immune responses can prolong the length of infection in Plasmodium falciparum malaria.

We have recently proposed a new model for antigenic variation in Plasmodium falciparum that relies on a network of partially cross-protective immune responses to orchestrate this complex immune evasion process. In addition to exhibiting prolonged oscillations of single variants that resemble the sequential dominance of immunologically distinct antigenic types, the model implies that a higher efficacy of cross-reactive immunity actually increases the length of infection while reducing severity of disease. Here, we analyse the behaviour of a reduced system under conditions of perfect synchrony between variants to demonstrate that these features of this system can be attributed to the antagonism between cross-reactive and variant-specific responses.