Ivermectin‐facilitated immunity in onchocerciasis; activation of parasite‐specific Th1‐type responses with subclinical Onchocerca volvulus infection

SUMMARY The present study examined the quantitative and qualitative changes registered in the parasite‐specific antibody response, cellular reactivity and cytokine production profile in onchocerciasis patients repeatedly treated with ivermectin over a period of 8 years. The densities of Onchocerca volvulus microfilariae (mf) in treated patients remained significantly reduced, whereas the number of permanently amicrofilaridermic patients (subclinical infection) increased with repeated treatments. In vitro cellular responses to O. volvulus antigen (OvAg) were highest (P