Blood stage-induced Plasmodium brasilianum infection in the squirrel monkey induces antibodies which react with the circumsporozoite protein.

A blood stage-induced P. brasilianum infection in a naive squirrel monkey induced antibodies which reacted with the circumsporozoite protein of the parasite. Titers increased with duration of infection and persisted for 3 months after cure. In an immunoblot, these antibodies detected two polypeptides with molecular weights identical to those of the circumsporozoite protein and its precursor.