Obesity, Diabetes Mellitus, and COVID-19: A Review of Evidence .

Growing evidence continues to show that obesity and diabetes are major contributors to poor COVID-19 outcomes, with consistent associations across studies linking both conditions to higher disease severity, ICU admission, and mortality. When it comes to vaccination, the picture is less clear. Trial data from Pfizer, Moderna, and Janssen suggest that vaccine efficacy is generally preserved in individuals with obesity or diabetes, yet emerging observational studies hint that immune responses may be lower in these groups. Because current evidence is limited and sometimes conflicting, strong conclusions cannot be drawn. For now, avoiding speculation is essential to maintain public trust, support vaccine uptake, and ensure that those at highest risk remain protected as research continues.