The provincial committee responsible for reviewing the adverse event or NISEC uses the World Health Organization (WHO) algorithm to examine what is reported about the event, including the case investigation form, the patient’s clinical details, standard case definitions from the Brighton collaboration (, currently available literature regarding vaccine adverse events, and product- related data from the manufacturers. When all the data is put together, the committee categorises the event as being:

‘consistent with a causal association to immunisation’. This includes ‘vaccine product-related reactions, vaccine quality defect-related reactions’,
‘Immunisation error-related reactions’ or ‘Immunisation anxiety- related reactions’.
a co-incidental event
temporally associated with vaccination but without definitive evidence for vaccine causing the event