Preliminary studies: Malarial parasite rates in villages were 57% in children and 41% in adults. A 30% increase in recorded cases was seen between 1995 and 1996. In May 1995 there was a measles outbreak with 29% mortality. Mortality was often associated with secondary bacterial infections, thus immunosuppression was suspected. Dr. Quakyi proposed that the TH1 responses elicited by malaria and the TH2 responses elicited by measles may result in anergy. Malarial AMA antibodies were similar by ELISA in both measles and non-measles groups, however, lower measles antibodies were observed for people with malaria parasitemia, than people who were parasite negative. These findings have an important public health indication for the endemic area Measles vaccinations will probably be less effective if given during the high parasitemia season, therefore, they should be given at the low malaria season. Children being vaccinated for measles at Yaounde hospital will be invited to return and have their blood drawn at regular intervals in order to determine the levels and duration of measles and malarial antibodies, the categorization of TH1/TH2 responses via cytokine and isotyping assays, and the proliferative responses of PBMC to measles and malarial antigens. This work will hopefully lead to enough data form the basis for a RO1 application.