LYMPHOCYTE-RESPONSE TO TETANUS TOXOID AMONG INDONESIAN MEN IMMUNIZED WITH TETANUS-DIPHTHERIA DURING EXTENDED CHLOROQUINE OR PRIMAQUINE PROPHYLAXIS

Immune suppression, a potential side effect of long-term chemoprophyla xis, was evaluated as part of a randomized, placebo-controlled trial t hat compared daily primaquine against weekly chloroquine for malaria p revention. In the last month of the year-long trial, baseline in vitro lymphoproliferative responses to tetanus toroid were measured, and a tetanus-diphtheria (Td) immunization was administered. Proliferative r esponses to tetanus toxoid in each Td-immunized group increased signif icantly over pre-Td baselines and those of the unvaccinated control, H ighest initial responses were measured in the primaquine group, The pr oportion of responders and the magnitude of proliferation was consiste ntly low in the chloroquine group, and end point responses in this gro up were significantly below those of the placebo, These results sugges t that the development and duration of the cellular response to tetanu s immunization was impaired by long-term weekly chloroquine prophylaxi s, while daily primaquine prophylaxis over the same time period had no inhibitory effect.