The Third Dose of the SARS-CoV-2 Vaccine: Why and for Whom?

The authors of this brief commentary give an update on the results of the last studies on the antibody response to the so-called “booster” administration of the Severe Acute Respiratory Syndrome (SARS)-CoronaVirus (CoV)-2 vaccines, with particular reference to the new “omicron” variant. A brief overview of the immunological response to this infection is also provided, with the advise that a serological test before the third dose of the vaccine is not recommended, as stated by the Food and Drug Administration (FDA).