Efficacy of flu vaccine lessened in obese people
A recent study from the United States has shown that the annual flu vaccine may not maintain the same level of effectiveness in people who are obese compared to their normal weight counterparts.
The research, which took place at the University of North Carolina at Chapel Hill, involved studying participants at a clinic who had received their annual flu vaccination in 2009. The vaccine was the common variety for the autumn and winter season; the inactivated trivalent influenza vaccine. Everyone who received the vaccine, whatever their weight, developed the flu virus antibodies as expected within the first four weeks following the vaccination. However, the levels of these antibodies in the blood showed a significantly more rapid decline in people who were either obese or overweight than in those participants were of normal weight.
After 12 months, blood samples from the participants were analysed. The analysis showed that approximately 75% of healthy weight individuals still had the necessary proteins to fight the infection. In comparison, only around 25% of those classified as obese had these proteins. One of the senior authors of the study, Melinda Beck, a PhD professor and also the associate chair of nutrition at the University of North Carolina Gillings School of Global Public Health, said in a statement that “[t]hese results suggest that overweight and obese people would be more likely than healthy weight people to experience flu illness following exposure to the flu virus.”
A large body of research exists which shows the disadvantages of being overweight or obese, including serious potential health complications such as cardiovascular disease. This is one of the first pieces of research to link obesity with reduced efficacy of the flu vaccine.