FIGURE 2.
Obesity potentially reduces long‐term COVID‐19 vaccination efficacy. Obesity alters PD1 and PD‐L1 expression on Tem cells, weakening stem cell responsiveness. Also, obesity is associated with elevated systemic ROS causing shorter telomere length of immune cells, leading to decreased Tem and Bm proliferation. Moreover, high serum leptin levels, as observed in obesity, reduces AID and E47 expression in B cells, inducing B cell class‐switching defects, potentially leading to decreased SARS‐CoV‐2‐specific‐IgG production. These factors together reduce long‐term protection against re‐infections. Therefore, despite COVID‐19 vaccination, patients with obesity may still be vulnerable for re‐infection with SARS‐CoV‐2. AID, activation‐in induced cytidine deaminase; Bm, B memory cells; IgG, immunoglobulin G; PD1, programmed cell death protein 1; PD‐L1, programmed death‐ligand 1; ROS, reactive oxygen species; Tem effector memory T cells