Does COVID-19 Vaccination Warrant the Classical Principle ""?

The current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic warrants an imperative necessity for effective and safe vaccination, to restrain Coronavirus disease 2019 (COVID-19) including transmissibility, morbidity, and mortality. In this regard, intensive medical and biological research leading to the development of an arsenal of vaccines, albeit incomplete preconditioned evaluation, due to emergency. The subsequent scientific gap raises some concerns in the medical community and the general public. More specifically, the accelerated vaccine development downgraded the value of necessary pre-clinical studies to elicit medium- and long-term beneficial or harmful consequences. Previous experience and pathophysiological background of coronaviruses' infections and vaccine technologies, combined with the global vaccines' application, underlined the obligation of a cautious and qualitative approach, to illuminate potential vaccination-related adverse events. Moreover, the high SARS-CoV-2 mutation potential and the already aggregated genetical alterations provoke a rational vagueness and uncertainty concerning vaccines' efficacy against dominant strains and the respective clinical immunity. This review critically summarizes existing evidence and queries regarding SARS-CoV-2 vaccines, to motivate scientists' and clinicians' interest for an optimal, individualized, and holistic management of this unprecedented pandemic.