The East African Community (EAC) Secretariat convened a cross-border Table Top Exercise (TTX) on 4-5 September 2018 at Mt. Meru Hotel, Arusha, Tanzania. GIZ supported the simulation through the “Support to Pandemic Preparedness in the EAC Region” (PanPrep) project; and the World Health Organization (WHO) led and coordinated the exercise design and implementation. The purpose of the simulation exercise was to strengthen and assess the capacity of the EAC Secretariat and the EAC Partner States to prepare and respond to public health events adopting a One Health approach. The experiences and key recommendations from the TTX will guide the design and implementation of the Field Simulation Exercise (FSX) which is planned for 11-14 June 2019. The FSX will build on the scenario used during the TTX, including an escalated fictitious scenario of a Rift Valley Fever (RVF)-like virus that is transmitted from animals to humans and can also be transmitted between humans.