Abstract
Τhe most promising approach of fighting COVID-19 and restraining the course of this pandemic is indisputably the universal vaccination of the population with safe and effective vaccines. However, besides the common and usually mild side effects of the authorized vaccines, some rare, major adverse reactions are increasingly being reported worldwide during the post marketing surveillance phase of vaccines' circulation, such as anaphylaxis, vaccine-induced thrombotic thrombocytopenia, myopericarditis and Guillain-Barré syndrome. Despite rare cases with complications from COVID-19 vaccines, the net benefit-risk ratio shows a clearly favorable balance towards COVID-19 vaccination for all age and sex groups. Vaccine adverse events should be identified early and monitored closely. As many aspects of these adverse effects remain still obscure for the medical community and the relevant stakeholders, it is also highly important to be promptly reported. Nonetheless, these complications should not constitute a reason to change the vaccine policy and further studies are needed to alleviate concerns and reluctance to COVID-19 vaccinations.