This research project examines the involvement of Brazilian public health experts in transnational epistemic communities during the Cold War, focusing on the period from 1955 to 1978. The study is framed around two pivotal World Health Organization (WHO) initiatives: the Malaria Eradication Program (1955) and the Smallpox Eradication Program (1959). For each program, a detailed case study is explored. The first investigates the "Pinotti" method, developed by Brazilian expert for malaria control in the Amazon, and its integration into WHO's Malaria Eradication Program in 1958. The second analyzes a containment-surveillance strategy used to eradicate smallpox in three Brazilian states. This research aims to illuminate the mechanisms of knowledge exchange within international health networks, while examining the roles, limitations, and impacts of these Brazilian experts in both local and global contexts, particularly from the perspective of actors often regarded as peripheral in global health initiatives.