The immune response of SARS-CoV-2 vaccine in population with obesity: a systematic review

Background: COVID-19 vaccines involve a humoral response to produce a neutralizing antibody that could protect subjects from severe COVID-19 infection. However, obesity tends to lower the immune response to the COVID-19 vaccine. Therefore, we conducted a systematic review to determine the immune response of various types of COVID-19 vaccines in a population with obesity. Methods: We conducted a systematic review based on The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. Using keywords, we search studies from Taylor & Francis, PubMed, ScienceDirect, Cochrane, and EBSCOHost. Results: We included eight cohort studies with 21,280 subjects after thorough selection and appraisal. Four studies stated that obesity was related to lower antibody titer post-SARS-CoV-2 vaccination, even though one study stated that obesity was not associated with long-term immune response. Another prospective cohort study involving approximately nine million populations stated that SARS-CoV-2 vaccination provided similar protection against COVID-19 compared to normoweight when underweight was a risk factor for lower protection. One study found that antibody titer wanes faster in obesity compared to normoweight. In addition, another study found lower antibody titer in obese men, whereas no significant findings were found in obese women. Conclusion: Therefore, it should be noted that COVID-19 vaccination in an obese population tends to provide a lower immune response regardless of vaccine type and doses are given. This should inform clinicians who want to administer the COVID-19 vaccine to obese populations.