Supplementary Table 6.

Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) Criteria for Studies Included in the Meta-Analysis of Case Control Studies Comparing Serologic Response After 2 Doses of Messenger RNA Vaccine to Controls

No. of participants	Starting level of evidence	Quality assessment					Reasons to increase level of evidence (large magnitude of effect; dose-response gradient; potential confounding)	Overall quality of evidence
		Risk of bias	Inconsistency	Indirectness	Imprecision	Publication bias
1188 (cases) and 499 (controls)	Low	Not serious	Serious	Serious	Not serious	Not serious	N/A	Low

N/A, not applicable.