We would like to share ideas on ‘Kounis syndrome must be considered in the differential diagnosis of myocardial infarction following COVID-19 vaccination’. Allam et al. concluded that ‘We want to emphasize that allergic reactions following COVID-19 vaccination can cause cardiac injury. There are multiple reported cases of acute myocardial infarction occurring within minutes to hours after’. The myocardial infarction following COVID-19 vaccination is an important clinical concern at present. There are many proposed underlying mechanisms for myocardial infarction. Adding to the Kounis syndrome, the infarction might also be due to the increased blood viscosity after the COVID-19 vaccination., A patient might also have an underlying disease that might be triggered for further development of cardiovascular problems when there is an excessive change of blood viscosity after COBVID-19 vaccination. Finally, the myocardial infarction in a COVID-19 vaccine recipient might also be due to other concurrent medical problems. The case of myocardial problem during waiting for COVID-19 vaccination is the best example. We would like to emphasize that while the COVID-19 vaccine might induce a cardiac problem, the vaccine is not the only possible cause of cardiac infarction observed after vaccination.Conflict of interest. None declared.