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). The gene discussed is INS; the disease is COVID-19.