The public health and the question of the "best vaccine"

Starting from December 2020, the immunization campaign against SARS-COV-2 has begun in Italy. The Italian Immunization Plan provided for the use of the four vaccines authorized by the European Medicine Agency, two RNA vaccines (Comirnaty, Pfizer and Spikevax, Moderna) and two viral vectored vaccines (Vaxzevria, Astrazeneca and Ad26.COV2.S COVID-19 vaccine, Jansen). RNA vaccines were recommended for healthcare workers, people aged 80 years or older or affected by chronic conditions that increased the risk of complications in case of COVID; on the other hand, the recommendations about the use of viral vectored vaccines changed more times during the immunization campaign. Viral vectored vaccines were, at the beginning of the immunization campaign, recommended for people younger than 50 years old; in March 2021, these vaccines were suspended for the weeks following the news of some adverse events resulting from the immunization process, specifically thrombosis among young women. Finally, viral vectored vaccines were recommended for people greater than 60 years; in fact, in this age class, the risk of vaccine related thrombosis seemed lower and, so, acceptable.