Fig. 1.

Immunogenicity of the BNT162b2 vaccine. SARS-CoV-2 (IgG II Quant, Abbott) peak antibody titers from 63 individuals. The moment of administration of the two doses is marked with a triangle and the sampling times are counted from each one of them. The time elapsed between the two vaccine administrations ranged between 21 and 28 days. Some of the individuals with pre-existing immunity had antibody titers below detection level (21 AU) or below the level established by the manufacturer (50 AU) in the days prior to vaccination.

* The IgG values from these four individuals (orange circles) were only taken into account to analyze the effects of the first dose of the vaccine.