Every year between September and November flu shot season is in full swing as people try to ward off the risk of contracting the year’s flu. Previous studies have shown that obesity can affect one’s ability to fight infection, but now a new study indicates that obesity may make one’s yearly flu shot less effective.
The study appeared in the October 25th issue of International Journal of Obesity. Researchers found that those who were obese or overweight not only had an increased risk of developing more severe illnesses if they caught the flu but the flu shot itself did not maintain as strong an antibody response in those with extra pounds compared with those of normal weight.
The researchers studied 74 people who had been given the 2009 to 2010 season flu vaccine that contained three strains of flu virus. The group of mostly women, was divided into thirds, so one third was normal weight, one third overweight and one third obese.
At the one month mark the level of antibodies produced by all the groups was roughly the same. However, 11 months later, the obese group had a four-fold decrease in their antibody levels while the normal weight group only had a 25 percent drop according to The New York Times.
Researchers also measured CD8 T cell count (white blood cells that help to fight a flu infection) in the group. Those with greater body mass had lower counts of these immunity protective cells.
"Over time, overweight and obese people are not maintaining their antibody levels to the extent that healthy weight people are," said study author Heather A. Paich, a graduate student at the University of North Carolina at Chapel Hill. "They also appear to have difficulty fighting the flu infection when it does occur," reported a Health Day news article.
Dr. Dr. Neil Schachter, a professor of pulmonary medicine at Mount Sinai School of Medicine in New York City went on to suggest that perhaps obese people should be candidates for the double flu shot practice, similar to a practice done in elderly patients. Because the older population is at a high risk of getting the flu, some are given a flu shot in the early fall then again in January.