The Global One Health initiative (GOHi) is assisting the Ethiopian Food and Drug Authority (EFDA) in assessing adverse events following immunization, particularly focusing on the novel Oral Poliovirus Vaccine type 2. A team of 28 health professionals conducted a causality assessment in Bishoftu, Ethiopia, in early April, evaluating 11 adverse events – 10 associated with nOPV2 and one with pneumococcal conjugate vaccine reported from recent vaccination campaigns. The team included members of the pharmacovigilance advisory committee, experts from the EFDA and representatives from the National Immunization Program and the Ethiopian Public Health Institute. This assessment resulted in recommendations to the EFDA and the Federal Ministry of Health aimed at enhancing the regulatory framework and safety measures for immunization programs in Ethiopia.