Supplementary Table 5.

Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) Criteria for Studies Included in the Meta-analysis of Observational Studies Assessing Serologic Response After 2 Doses of Messenger RNA Vaccine

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
2505	Low	Not serious	Not serious	Serious	Not serious	Not serious	Not applicable	Low