Aluminum adjuvants are used in vaccine manufacturing to "stimulate" the immune system  The presence of aluminium adjuvants has been associated with injection-site reactions such as nodules, granulomas and erythema.  aluminium adjuvants may lead to the syndrome macrophagic myofascitis, a histological finding where aluminium-containing macrophages infiltrate muscle tissue, and may be accompanied by a clinical syndrome of myalgia, arthralgia and fatigue.  A systematic review of controlled safety studies reported that vaccines containing aluminium produce more erythema and induration than other vaccines in young children (up to 18 months of age), and greater local pain in older children (10–18 years).


Animal and human studies have shown that aluminum can cause nerve cell death [1] and that vaccine aluminum adjuvants can allow aluminum to enter the brain, [2,3] as well as cause inflammation at the injection site leading to chronic joint and muscle pain and fatigue. [4,5]

References:
1. Kawahara M et al. 2001. Effects of aluminum on the neurotoxicty of primary cultured neurons and on the aggregation of betamyloid protein. Brain Res. Bull. 55, 211-217.
2. Redhead K. et al. 1992. Aluminum-adjuvanted vaccines transiently increase aluminum levels in murine brain tissue. Pharmacol. Toxico. 70, 278-280.
3. Sahin G. et al. 1994. Determination of aluminum levels in the kidney, liver and brain of mice treated with aluminum hydroxide. Biol. Trace. Elem. Res. 1194 Apr-May;41 (1-2):129-35.
4. Gherardi M et al. 2001. Macrophagaic myofastitis lesions assess long-term persistence of vaccine-derived aluminum hydroxide in muscle. Brain, Vol 124, No. 9, 1821-1831.
5. Shingde M eta la. 2005. Macrophagic myofastitis associated with vaccine derived aluminum. MJA, 183 (03):145-146. Hide.