IgG Antibody Response to the Pfizer BNT162b2 SARS-CoV-2 Vaccine in Healthcare Workers with Healthy Weight, Overweight, and Obesity.

Obesity is a significant factor for increased morbidity and mortality upon infection with SARS-CoV-2. Because of the higher potential for negative outcomes following infection of individuals with obesity, the impact of body mass index (BMI) on vaccine immunogenicity and efficacy is an important public health concern. Few studies have measured the magnitude and durability of the vaccine-specific response in relation to BMI. We measured the receptor binding domain (RBD)-specific serum IgG and surrogate neutralizing titers in a cohort of 126 vaccinated individuals with no clinical history or serological evidence of previous SARS-CoV-2 infection 50 and 200 days following vaccination. BMI had no significant impact on RBD-specific IgG titers and surrogate neutralizing titers 50 days following immunization, and leptin levels had no correlation with the response to immunization. Two hundred days following immunization, antibody titers in all groups had declined by approximately 90%. The responses were also similar between male and female participants and did not significantly vary across age groups. These results indicate that the magnitude and durability of the antibody response to mRNA-based vaccines are unaffected by BMI in this cohort.