Enhancing Immune Response to Influenza Vaccine

Flu vaccinations work by "training" the immune system to be resistant to specific strains of viruses that cause the flu. This process requires that the body's immune system respond to the vaccination. Some supplements may enhance your immune response to the vaccine, making it more effective at preventing the flu.

Asmall double-blind study found evidence that use of the probiotic bacteria Lactobacillus fermentum improved the effectiveness of the influenza vaccine.¹⁵⁸ The probiotic supplement was taken in two doses: one, two weeks before the vaccine, and the other, two weeks after.

Some seniors do not respond fully to the influenza vaccine. There is some evidence that vitamin E supplements may strengthen the immune response to vaccinations.⁷⁴ Similarly, evidence from two double-blind trials,^93,94 but not a third,¹⁰² suggests that combined multivitamin/multimineral supplements may improve their response. However, in another trial, a multivitamin tablet without minerals actually worsened participants' response to the vaccine.⁹⁵ The reason for these discrepancies is unclear; however, concerns have been raised that one of the scientists who reported benefits in some of these trials engaged in questionable scientific practices.

In a double-blind, placebo-controlled study of 124 people, the supplement chlorella at a dose of 200 mg or 400 mg daily failed to enhance response to influenza vaccine.¹²⁹ Another study failed to find benefit with a remedy from Traditional Chinese Herbal Medicine, Hochu-ekki-to.¹³⁶

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94. Chandra RK, Puri S. Nutritional support improves antibody response to influenza virus vaccine in the elderly. Br Med J (Clin Res Ed). 1985;291:705-706.
95. Ender PT, DeRussy PK, Caldwell MM, et al. The effect of a multivitamin on the immunologic response to the influenza vaccine in the elderly. Infect Dis Clin Pract. 2001;10:81-85.
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129. Halperin SA, Smith B, Nolan C, et al. Safety and immunoenhancing effect of a chlorella-derived dietary supplement in healthy adults undergoing influenza vaccination: randomized, double-blind, placebo-controlled trial. CMAJ. 2003;169:111-117. 136.Hamazaki K, Sawazaki S, Itomura M, et al. No effect of a traditional Chinese medicine, Hochu-ekki-to, on antibody titer after influenza vaccination in man: A randomized, placebo-controlled, double-blind trial. Phytomedicine. 2006 Apr 24. [Epub ahead of print]
158. Olivares M, Diaz-Ropero MP, Sierra S, et al. Oral intake of Lactobacillus fermentum CECT5716 enhances the effects of influenza vaccination. Nutrition. 2007;23:254-260.