Factors affecting production of antibodies

Factors affecting production of antibodies

Factors affecting production of antibodies

Many factors affect the production of antibodies. These factors are discussed below:

  1. Genetic factors
  2. Age
  3. Nutritional status
  4. Route of antigen
  5. Dose of antigen
  6. Multiple antigens
  7. Adjuvants

Genetic factors:

  • Genetic factors influence the response of the host to antigen.
  • Persons responding to antigens are called responders, while persons not responding are called nonresponders.
  • These differences are controlled genetically and are being controlled by immune response (Ir) gene located in the short arm of the 6th chromosome.


  • The embryo and the infant, at birth, are not fully immunologically competent.
  • Full competence is achieved by about the age of 5–7 years for IgG and 10–15 years for IgA by the development of lymphoid organs.

Nutritional status:

  • Malnutrition affects both the humoral and cell-mediated immunities.
  • Deficiencies of amino acid and vitamins have shown to decrease the production of antibodies.

Route of antigen:

  • Induction of immune response in a host depends on the route of administration of the antigen.
  • Parenteral administration of the antigen induces a better immune response than the oral or nasal routes.

Dose of antigen:

  • A minimum critical dose of antigen is essential to elicit an optimum immunological response.
  • A very high or small dose fails to stimulate the immune system.
  • This phenomenon is referred to as immunological paralysis.

Multiple antigens:

  • Antibody responses vary when two or more antigens are administered simultaneously.
  • Antibody responses to one or more of them may be diminished due to antigenic competition, or enhanced as seen after vaccination with triple vaccine (diphtheria, pertussis, and tetanus), or may be similar.
  • Hence, the nature and relative proportions of different antigens should be carefully adjusted for optimal effect.


  • Adjuvants are the substances that enhance the immunogenicity of an antigen.
  • The adjuvants delay the release of an antigen from the site of injection and prolong the antigenic stimulus.

The substances that are used as adjuvants include:

  1. Freund’s incomplete adjuvant (protein antigen incorporated in water phase of water in oil emulsion).
  2. Freund’s complete adjuvant (incomplete adjuvant along with suspension of killed tubercle bacilli).
  3. Aluminum salts both phosphate and hydroxide.
  4. Others, such as silica particles, beryllium sulfate, endotoxin, etc.

Factors affecting production of antibodies




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