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Adjuvant

Also known as: Immunostimulant

Adjuvant (from Latin adjuvans — helping, supporting) is a specific pharmacological component added to the composition of some modern vaccines. Its main task is to enhance the body’s immune response to the administered vaccine antigen.

Etiology and pathophysiology

Historically, the first vaccines were created from whole, albeit killed, microbes. They were reactogenic but provided strong immunity as they contained many natural “danger signals”.

Modern vaccines are maximally safe. They consist of:

active component — weakened viruses, killed microorganisms, their parts (proteins, sugars), or genetic material;
various auxiliary substances, one of which are adjuvants.

An adjuvant enhances local immunity (serves as a chemical siren attracting a significant number of various immune system cells to the injection site), which allows for the use of lower doses of antigens in the vaccine.

Clinical significance

The most commonly used adjuvants are aluminum salts (hydroxide or phosphate).

Undesirable post-vaccination effects (swelling, redness, induration, and pain at the injection site) are often caused by adjuvant penetration into the subcutaneous fat.