Adverse Events Following Immunization with Novel Oral Polio Vaccine Type 2, and the Experience and Challenges of Reporting in Sierra Leone [Letter]

We are very interested in the research titled "Adverse Events Following Immunization With Novel Oral Polio Vaccine Type 2, and the Experience and Challenges of Reporting in Sierra Leone" which explores the effectiveness and challenges of vaccinating children affected by the polio outbreak in Sierra Leone. 1 This paper briefly and clearly describes the emergence of the cVDPV2 outbreak in Sierra Leone, which affected children in the country.Besides that, this study uses a mixed-method approach and a dense population to describe the effectiveness of vaccine implementation and the extent to which vaccine implementers achieve success and overcome various obstacles.However, more work is needed to add a medical perspective on AEFI, and provide hypotheses related to adverse events.There is a need for focus group discussion to understand the participants who are vaccinators and to get a more specific sketch and capture a more complete perception of the client. 2In addition, an explanation or narrative about of AEFI is needed based on findings in the field, and to reinforce the finding that vaccination has no causal relationship to the occurrence of AEFI.Thus, the public does not need to be afraid to receive vaccines, because it is clear that the cause of adverse symptoms is not caused by vaccination.