Table A1. Ratings for strength of National Advisory Committee on Immunization (NACI) recommendations and grade of evidence.

Strength of NACI recommendation based on factors not isolated to strength of evidence (e.g. public health need)	Strong	Discretionary
Wording	"should/should not be offered"	"may be considered"
Rationale	Known/anticipated advantages outweigh known/anticipated disadvantages ("should"), OR known/anticipated disadvantages outweigh known/anticipated advantages ("should not")	Known/anticipated advantages closely balanced with known/anticipated disadvantages, OR uncertainty in the evidence of advantages and disadvantages exists

Implication

A strong recommendation applies to most populations/individuals and should be followed unless a clear and compelling rationale for an alternative approach is present

A discretionary recommendation may be considered for some populations/individuals in some circumstances Alternative approaches may be reasonable

Grade of evidence
based on assessment of the body of evidence

A: good evidence to recommend B: fair evidence to recommend C: conflicting evidence, however other factors may influence decision-making D: fair evidence to recommend against E: good evidence to recommend against I: insufficient evidence (in quality or quantity), however other factors may influence decision-making