Robust cellular immune responses to BNT162b2 SARS-CoV-2 mRNA vaccine in T2DM individuals in Bangladesh           

  Introduction: Diabetes being one of the most common comorbidities of COVID-19, is prioritized for SARS-CoV-2 vaccination. To evaluate the T-cell mediated immune responses in T2DM, this study assessed and compared IFN-\(\gamma\) and IL-2 secreting PBMCs against the SARS-CoV-2 BNT162b2 mRNA vaccine.  Methods: : 19 known cases of type 2 diabetes and 16 healthy controls were included through purposive sampling and were regularly sampled before 1 st dose, after 1 st and 2 nd dose of vaccination. Ex-vivo ELISpot assays for IFN-\(\gamma\) and IL-2 were done using isolated PBMCs along with HbA1c status and SARS-CoV-2 spike-specific IgG antibody. A  p -value < 0.05 was considered significant.  Results: : All participants were seroconverted after 1 st dose and showed a robust rise of IFN-\(\gamma\) and IL-2 secreting PBMCs counts in T2DM participants irrespective of hypertension, gender and age after 2 doses of vaccination. However, IFN-\(\gamma\) secreting PBMCs counts were significantly lower in type 2 diabetic group than healthy control group after 1 st dose.  Conclusion: Although type 2 diabetic participants had a lower response initially, BNT162b2 mRNA vaccine overall induces a robust T-cell mediated immune response