Acute corneal graft rejection and COVID-19 vaccination: Correspondence

Dear Editor, we would like to share ideas on the publication “Acute corneal graft rejection after anti-severe acute respiratory syndrome-coronavirus-2 vaccination: A report of four cases”. Balidis et al. concluded that “Even though a direct causative effect is hard to prove, temporal proximity between anti-severe …..must be given to corneal transplant patients regarding such risk.^[1]“ We agree that COVID-19 vaccine might cause some uncommon adverse effects. Corneal graft rejection might be a clinical problem following COVID-19 vaccination. As Balidis et al. noted, it is difficult to conclude for relationship. Whether graft rejection is a coincidence is usually a common question. It is generally believed that immunological abnormality induced by vaccine might be the cause of adverse event. However, there is usually no data on abnormal immune parameters in affected case and there is usually no data on pre-vaccination immune status. If there is an abnormal immunity, graft rejection might be the result.^[2] Other possible causal mechanism of graft rejection is high blood viscosity after vaccination which directly affects survival of graft.^[3] To ensure a safety, vaccination should still be postponed for the case just receiving corneal graft transplantation.