IntroductionPrior studies have identified various determinants of differential immune responses to COVID-19. This investigation delves into the Ig-G anti-RBD marker, scrutinizing its potential correlations with sex, vaccine type, body fat percentage, metabolic risk, perceived stress, and previous COVID-19 exposure.MethodsIn this study, data were obtained from 116 participants from the ESFUERSO cohort, who completed questionnaires detailing their COVID-19 experiences and stress levels assessed through the SISCO scale. Quantification of Ig-G anti-RBD concentrations was executed using an ELISA assay developed by UNAM. Multiple regression analysis was adeptly employed to control for covariates, including sex, age, body fat percentage, BMI, and perceived stress.ResultsThis sample comprised young individuals (average age of 21.4 years), primarily consisting of females (70%), with a substantial proportion reporting a family history of diabetes, hypertension, or obesity. Most students had received the Moderna or Pfizer vaccines, and 91% displayed a positive anti-RBD response.A noteworthy finding was the interaction between body fat percentage and sex. In males, increased adiposity was associated with a decrease in Ig-G anti-RBD concentration, while in females, the response increased. Importantly, this trend was consistent regardless of the vaccine received. No significant associations were observed for variables such as dietary habits or perceived stress.ConclusionsIn summation, this research reports the impact of both sex and body fat percentage on the immune response through Ig-G anti-RBD levels to COVID-19 vaccines. The implications of these findings offers a foundation for educational initiatives and the formulation of preventive policies aimed at mitigating health disparities.