Interestingly, we found that mice administered four doses of the COVID‐19 vaccine (week 4) exhibited impaired glucose tolerance, as evaluated by the oral glucose tolerance test (OGTT), fasting blood glucose (FBG), and serum insulin levels (p < 0.05, Figure 1E,F; n.s. for Figure 1G,H). This evidence concerns the gene INS and Impaired glucose tolerance.