Association between diet quality and BMI with side effects of Pfizer-BioNTech COVID-19 vaccine and SARS-CoV-2 immunoglobulin G titers

Purpose The nutritional and anthropometric status can be essential in determining their immune response to vaccines. The purpose of this paper was to investigate the association between diet quality and anthropometric indices with the side effects of the Pfizer-BioNTech COVID-19 vaccine and the SARS-CoV-2 immunoglobulin G titer among Kurdish adults. Design/methodology/approach This cross-sectional survey-based study was conducted between December 2021 and February 2022. This paper included data on 115 adults, 20–89 years old, from the Kurdistan region. Dietary information was collected using a short food frequency questionnaire, and diet quality was assessed using a plant-based healthy diet score. A blood test was performed to measure the SARS-CoV-2 immunoglobin G (IgG) titer after the vaccination's first and second doses. Findings Overweight and obese subjects reported more local pain, myalgia, headache, local bruising and local reactions after receiving the first dose of the vaccine (p = 0.04). People on a less healthy diet reported more local pain, myalgia and headache (p = 0.04) and more local bruising and reactions (p = 0.01) after receiving the second dose of the vaccine. On the other hand, the authors observed that those with healthy dietary habits had more IgG titer after the first and second doses of vaccination than those with less healthy dietary habits (p = 0.001). Originality/value The results showed that participants with a healthy diet and normal weight status had fewer side effects of the Pfizer-BioNTech COVID-19 vaccine than obese people and those with a less healthy diet.