The BNT162b2 COVID-19 vaccine is known to induce a rapid production of neutralizing antibodies (Lustig et al., 2021; Vicenti et al., 2021b); however, there are very limited data on their long-term kinetics. Favresse et al. (2021b) described a robust humoral response 90 days after the first dose of vaccine both in previously seropositive and seronegative subjects, but a significant antibody decrease in respect to the higher level reached occurred within this period. Interestingly, the administration of a third dose of the BNT162b2 vaccine, about two months from the second dose, to solid-organ transplant recipients significantly improved the immunogenicity of the vaccine (Kamar et al., 2021).
