Central obesity, smoking habit and hypertension are associated with a blunted serological response to COVID-19 mRNA vaccine

AimsTo explore variables associated with the serological response following COVID-19 mRNA vaccine. MethodsHealthcare workers adhering to the vaccination campaign against COVID-19 were enrolled in January-February 2021. All subjects underwent two COVID-19 mRNA vaccine inoculations (Pfizer/BioNTech) separated by three weeks. Blood samples were collected before the first and 1-4 weeks after the second inoculation. Clinical history, demographics, and vaccine side effects were recorded. Baseline anthropometric parameters were measured, and body composition was performed through dual-energy-X-ray absorptiometry. ResultsEighty-six patients were enrolled. Those with central obesity had lower antibody (Ab) titers compared with those with no central obesity [1426(1436)vs1971(1819), p=0.04]; smokers had a blunted response compared to non-smokers [1099(1350)vs1921(1375), p=0.007], as well as hypertensive vs normotensive [650{+/-}1192vs1911(1364), p=0.001] and dyslipidemic compared to those with normal serum lipids [534(972)vs 1872(1406), p=0.005]. Multivariate analysis showed that higher waist circumference, smoking, hypertension and longer time elapsed since second vaccine inoculation were associated with lower Ab titers, independent of BMI, age and gender. The association between waist circumference and Ab titers was lost when controlling for body fat, suggesting that visceral accumulation may explain this result. ConclusionsIt is currently impossible to determine whether lower SARS CoV-2 Abs lead to higher likelihood of developing COVID-19. However, neutralizing abs correlate with protection against several viruses including SARS-CoV-2, and the finding that central obesity, hypertension and smoking are associated with a blunted response warrants further attention. Our findings must lead to a vigilant approach, as these subjects could benefit from earlier vaccine boosters or different vaccine schedules.