evidence: To this day, the aluminium in vaccines is always in the form of salts. These include aluminium hydroxide (commonly used as an antacid to relieve indigestion and heartburn), aluminium phosphate (often used in dental cement) and potassium aluminium sulphate, which is sometimes found in baking powder. [...] One theory is that the toxicity of aluminium salts is, paradoxically, the reason they work. They lead distressed cells to release uric acid, which activates an immune reaction normally associated with damage. Immune cells flock to the site, and start producing antibodies – and voila, the vaccine has worked.