Covid-19 disease and SARS-COV-2 vaccines: the balance between risks and benefits

Abstract

The infection with the new SARS-CoV-2 coronavirus has caused more than 4.5 million victims worldwide, and this number continues to rise. As more than 3 billion people have been vaccinated, COVID-19 vaccines shown an excellent efficacy and an acceptable safety profile. With the availability of SARS vaccines for an increasing number of people, several sporadic cases of adverse events have been reported, suggesting a causal relationship between these two phenomena. However, when it comes to the safety profile of SARS-CoV-2 vaccines, an important issue is that these risks should be balanced against the risks of exposure to COVID-19, an infection which itself can lead to lung damage but also to thrombotic /thromboembolic events. Increased risk of hematological and vascular events leading to hospitalization or death at short intervals after the first doses of ChAdOx1 nCoV-19 and BNT162b2 vaccines has been observed. Myocarditis is a very rare side effect associated with the BNT162b2 vaccine, which is 6-folds more likely to occur after SARS-CoV-2 infection compared to the vaccine itself. The risks of most of these events were substantially higher and more prolonged after SARS-CoV-2 infection than after vaccination in the same population.