Figure 1.

Causality assessment of “Adverse Events Following Immunization” (AEFIs) after “Coronavirus Disease 2019” (COVID-19) vaccination based on the World Health Organization (WHO) guidelines, which propose a comprehensive four-step analytical and algorithmic diagramming process (namely, evaluation and assessment of (i) the temporal association between vaccine administration and AEFI/immune-mediated disease (IMD); (ii) a plausible time window between vaccine administration and AEFI/IMD; (iii) other causes, such as underlying co-morbidities or drugs taken by the patient, which could explain the insurgence of AEFI/IMD; and, (iv) strength of the causal association, based on what is currently known from the literature).