June 7, 2017
Compared to adults of healthy weight, obese adults are twice as likely to contract the flu or a flu-like illness despite being vaccinated.
These findings were shared in an article titled, “Increased risk of influenza among vaccinated adults who are obese,” which was published online June 6 by the International Journal of Obesity.
Melinda A. Beck, PhD, professor and associate chair for academics in the Department of Nutrition in the UNC Gillings School of Global Public Health, is the corresponding author of the study.
During the 2013-2014 and 2014-2015 influenza seasons, Beck and co-authors assessed the relative risk, based on BMI, of laboratory-confirmed influenza and influenza-like illness for 1,022 study participants. All study participants had received the seasonal trivalent inactivated influenza vaccine. The researchers found that 9.8 percent of obese subjects ultimately became ill, compared to 5.1 percent of healthy-weight participants.
“The amount of antibody produced against influenza virus following vaccination is commonly used to predict protection against influenza,” Beck explained. “However, this study found no differences in the antibody levels between obese and healthy weight adults. This suggests that using antibody as a correlate of protection from influenza infection in an obese population may provide misleading information.”
Influenza poses a serious public health risk worldwide. As 37 percent of adults in the United States and 14 percent of adults globally are obese, addressing the ability of the influenza vaccine to protect obese people from infection is an urgent concern.
Other co-authors from the Gillings School include William D. Green, MS, graduate research assistant, and Jennifer Rebeles, MS, doctoral student, in the Department of Nutrition, and Sujatro Chakladar, MS, doctoral student, and Michael G. Hudgens, PhD, professor, in the Department of Biostatistics. Scott D. Neidich, PhD, first author of the study, completed this research as part of his doctoral thesis at UNC Gillings. He is now a postdoctoral researcher at Duke University’s Human Vaccine Institute.