Immunity to monomorphic Trypanosoma brucei: humoral response.

Trypanosome-agglutinating antibodies, predominantly of the IgM class, are formed in T. brucei-infected rats cured with Berenil (diminazene). The duration of Berenil prophylaxis following administration of a minimum curative dose is approximately 28 days. Rechallenge of drug-cured animals with homologous organisms results in the production of IgG, indicating an apparent absence of interference under these conditions with B-cell, T-cell cooperativity.