CYP2C9 and influenza: Studies have shown that different CYP3A4 polymorphisms are associated with varying risks of increased statin plasma levels or treatment outcomes, suggesting genetic variations in CYP3A4 may yield enzymatic variants that contribute to inter-individual differences in drug metabolism.47, 48, 49 By contrast, other studies have found that INF-γ production has only minor or no effect on CYP2C9.50, 51, 52 Further research should investigate whether interference in medication metabolism plays a significant role in potential interactions between influenza vaccination and statins.