Are adjuvants toxic?
Adjuvants, substances that increase the body's response to vaccines, have been used safely for decades. They are not inherently toxic. They are tested for safety and effectiveness before use. Aluminum salts, common adjuvants, are found in drinking water. The best adjuvants maximize immunogenicity (the ability of the vaccine to induce an immune response) without compromising tolerability or safety.
Regulatory guidelines for the clinical evaluation of new vaccines are available and are regularly reviewed and updated. The Food and Drug Administration says it seeks to ensure that any adjuvant "does not affect adversely the safety or potency of the product."
Each vaccine receives a pre-clinical safety evaluation, as different vaccines have different combinations of adjuvant and antigens, which induce the immune response.
