Aims: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‐CoV‐2) infection has had a serious worldwide impact on human health. On December 2020, an immunization campaign with a COVID‐19 mRNA vaccine (Comirnaty‐BNT162b2 Pfizer‐BioNTech) was started in Italy, first targeting healthcare workers (HCWs). This study aims to investigate the antibodies that are response against SARS‐CoV‐2 vaccine. Methods and Results: The kinetics and the persistence of both anti‐S1/S2 IgGs and neutralizing antibodies (Nt‐Abs) were investigated in 76 HCWs through a 4‐month follow‐up with multiple testing points starting at the first dose. Temporal analysis of SARS‐CoV‐2 Abs titre kinetics showed three different stages, with an initial slow growth in the anti‐S1/S2 IgGs and Nt‐Abs titres, corresponding to the first 4 weeks after the first dose of vaccine, followed by a second stage with peaks in titres, around 35 days after the first dose, and by a third stage (38 to 90–120 days after the first dose) showing a steady decrease in anti‐S1/S2 IgGs while Nt‐Abs are maintained at stable levels. Moreover, the levels of specific Nt‐Abs to SARS‐CoV‐2 Spike protein are correlated to the anti‐S1/S2 IgG titre (R‐squared = 0.47; p < 0.001). Conclusions: The levels of specific Nt‐Abs to SARS‐CoV‐2 Spike protein are correlated to the anti‐S1/S2 IgG titre, although Nt‐Abs could maintain a more stable titre over the time despite declining IgG Abs titre. Significance and Impact: This study highlights the kinetics and the persistence of Nt‐Abs in HCWs vaccinated with Comirnaty (BNT162b2) Pfizer‐BioNTech, and compared the Nt‐Abs levels with anti‐SARS‐CoV‐2 S1/S2 IgGs titres during a 4‐month follow‐up starting at the first dose of vaccine. [ABSTRACT FROM AUTHOR]