Aluminium salts example
Aluminium salts are among the oldest adjuvants that are commonly used. They slow the escape of the antigen from the site of injection, thereby lengthening the duration of contact between the antigen and the immune system (i.e. macrophages and other antigen-receptive cells).
Aluminium salts are generally recognized as safe; however, they can cause sterile abscesses and nodules at the site of injection. The formation of a small granuloma is inevitable with aluminium-precipitated vaccines.
To ensure safe vaccination it is important that aluminium salts are administered intramuscularly and not subcutaneously. Subcutaneous administration can result in necrotic breakdown and cyst and abscess formation. To ensure the proper handling of intramuscular injections, it is critical to ensure that vaccination staff has been well trained.