Robust antibody levels in both diabetic and non-diabetic individuals after BNT162b2 mRNA COVID-19 vaccination

Ali, H.; Al-Terki, A.; Sindhu, S.; Alahmad, B.; Hammad, M.; Al-Sabah, S.; Alghounaim, M.; Jamal, M. H.; Aldei, A.; Mairza, M. J.; Husain, M.; Devarajan, S.; Ahmad, R.; Cherian, P.; Alkhairi, I.; Alkandari, A.; Abubaker, J.; Abu-farha, M.; Al-Mulla, F.

The emergence of effective vaccines for COVID-19 has been welcomed by the world with great optimism. Given their increased susceptibility to COVID-19, the question arises whether individuals with type-2 diabetes mellitus (T2DM) and other metabolic conditions can respond effectively to the mRNA-based vaccine. We aimed to evaluate the levels of anti-SARS-CoV-2 IgG and neutralizing antibodies in people with T2DM and/or other metabolic risk factors (hypertension and obesity) compared to those without. This study included 262 people that took two doses of BNT162b2 (Pfizer-BioNTech) mRNA vaccine. Both T2DM and non-diabetic individuals had a robust response to vaccination as demonstrated by their high antibody titers. However, both SARS-CoV-2 IgG and neutralizing antibodies titers were lower in people with T2DM. Their levels were 154{+/-}49.1 vs. 138{+/-}59.4BAU/mL for IgG and 87.1{+/-}11.6 vs. 79.7{+/-}19.5% for neutralizing antibodies in individuals without diabetes compared to those with T2DM, respectively. In a multiple linear regression adjusted for individual characteristics, comorbidities, previous COVID-19 infection and duration since second vaccine dose, diabetics had 13.86 BAU/ml (95%CI: -27.08 to -0.64BAU/ml, p=0.041) less IgG antibodies and 4.42% (95%CI: -8.53 to -0.32%, p=0.036) less neutralizing antibodies than non-diabetics. Hypertension and obesity did not show significant changes in antibody titers. Taken together, both type-2 diabetic and non-diabetic individuals elicited strong immune responses to SARS-CoV-2 BNT162b2 mRNA vaccine; nonetheless, lower levels were seen in people with diabetes. Continuous monitoring of the antibody levels might be a good indicator to guide personalized needs for further booster shots to maintain adaptive immunity.