Little is known about the long-term durability of the induced immune response in subjects with obesity, particularly in those with an abdominal distribution of adipose tissue. We evaluated SARS-CoV-2-specific antibody responses after BNT162b2 vaccine booster dose, comparing individuals with and without abdominal obesity (AO), discerning between individuals previously infected or not. IgG-TrimericS were measured in 511 subjects at baseline, on the 21st day after vaccine dose 1, and at 1, 3, 6, and 9 months from dose 2, and at 1 and 3 months following the booster dose. To detect SARS-CoV-2 infection, nucleocapsid antibodies were measured at baseline and at the end of the study. Multivariable linear regression evaluated the three-month difference in the absolute variation in IgG-TrimericS levels from booster dose, showing AO and SARS-CoV-2 infection status interactions (p = 0.016). Regardless of possible confounding factors and IgG-TrimericS levels at the booster dose, AO is associated with a higher absolute change in IgG-TrimericS in prior infected individuals (p = 0.0125). In the same regression model, no interaction is highlighted using BMI (p = 0.418). The robust response in the development of antibodies after booster dose, observed in people with AO and previous infection, may support the recommendations to administer a booster dose in this population group.

Little is known about the long-term durability of the induced immune response in subjects af-fected by obesity, particularly in those with an abdominal distribution of adipose tissue. We evaluated SARS-CoV-2-specific antibody response after BNT162b2 vaccine booster dose, com-paring individuals with abdominal obesity (AO) with those without, discerning between indi-viduals previously infected or not. IgG-TrimericS were measured in 511 subjects at baseline, 21 days after vaccine dose-1 and at one, three, six and nine months after dose-2 and at one and three months after booster dose. Nucleocapsid antibodies were assessed at baseline and at the end of the study to detect SARS-CoV-2 infection. To evaluate the three-months difference in absolute variation of IgG-TrmicericS levels from booster dose we used multivariable linear regression that showed interaction between AO and SARS-CoV-2 infection status (p=0.016). AO is associated with higher absolute IgG-TrimericS variation in prior infected individuals, regardless of possi-ble confounders and IgG-TrimericS levels at booster dose (p=0.0125). No interaction was evinced using BMI in the same regression model (p=0.418). The robust response in the development of antibodies after booster dose, observed in people with OA and previous infection, may support the recommendations to undergo the booster dose also in this population group.