The benefits of multiple Plasmodium infections.

Children born in areas of high malaria-transmission take 3-5 years to develop immunity against infection and disease because they get continuously infected with different Plasmodium strains. Infection with different Plasmodium genotypes (the complexity of infection, COI) could potentially impact the development of malaria immunity in several ways. For example, infection with different genotypes could lead to he development of genotypes or allele-specific immunity (ie the host would develop resistance to immunologically defined genotypes whereas remain susceptible to other gentoypes). Hence, exposure to greater allecli diveristy in a single infection would lead to more rapid development of antiparasite immunity. However, field studies suggest that multiple genotype infections hamper the development of protective immunity against malaria, causing an antigenic smokescreen that results in immunological antagonism.