Immunostimulants are substances that stimulate the immune system.

1.  Immunostimulants are substances that stimulate the immune system.
 Specific immunostimulants such as vaccines stimulate an immune response to specific
antigenic types.
 Non-specific immunostimulants do not have antigenic specificity and are widely used
in chronic infections, immunodeficiency, autoimmunity and neoplastic diseases.
 Types of Immunostimulants
1. Bacterial vaccines
2. Colony stimulating factors
3. Interferons
4. Interleukins
5. Therapeutic vaccines
6. Vaccine combinations
7. Viral vaccines
1) Bacterial vaccines
 Bacterial vaccines contain killed or attenuated bacteria that activate the immune
system.
 Antibodies are built against that particular bacteria, and prevents bacterial infection
later.
 Eg: Tuberculosis vaccine, tetanus toxoid, typhoid vaccine (inactivated), cholera
vaccine (live) etc.
2) Colony stimulating factors
 Colony stimulating factors are glycoproteins that promote production of white blood
cells (mainly granulocytes such as neutrophils), in response to infection.
 Administration of exogenous colony stimulating factors stimulates the stem cells in
the bone marrow to produce more of the particular white blood cells. The new white
blood cells migrate into the blood and fight the infection.

2.  Colony stimulating factors are used in patients who are undergoing cancer treatment
that causes low white blood cell counts (neutropenia) and puts the patient at risk of
infection. Colony stimulating factors tend to reduce the time where patients are
neutropenic.
 Eg: filgrastim, pegfilgrastim, sargramostim
3) Interferons
 Interferons are proteins produced by tumor cells or host cells that are infected with
viruses, bacteria and other unknown nucleic acids.
 Interferons also activate other cells that serve as part of the immune system and
destroy invading pathogens.
 Interferons are classed as: alpha (from white cells), beta (from fibroblasts) and gamma
(from lymphocytes).
 Interferons enhance the immune system in many ways so can be used to treat different
conditions involving the immune system.
 Interferons used therapeutically are manufactured using recombinant DNA
technology.
 Interferon alphas are used to treat viral infections (chronic hepatitis, human
papillomavirus) and treating cancer (hairy cell leukemia, AIDS related - Kaposi
sarcoma, malignant melanoma).
 Interferon betas are used to treat or slow down the progression of multiple sclerosis.
 Interferon gamma is used to treat chronic granulomatous disease.
4) Interleukins
 Interleukins are a group of cytokines which are synthesized by lymphocytes,
monocytes, macrophages, and certain other cells. They function especially in
regulation of the immune system
5) Therapeutic vaccines
 Therapeutic vaccines are vaccines which are intended to treat or cure a disorder or
disease by stimulating the immune system.
 Therapeutic vaccines may be used to treat certain types of cancer, by stimulating the
body's immune system to help it respond against certain cancer cells.
 They may also be used in the prevention of tuberculosis in persons not previously
infected with M. tuberculosis who are at high risk for exposure.

3. 6) Vaccine combinations
 Vaccine combinations merge antigens that prevent different diseases or that protect
against multiple strains of infectious agents causing the same disease, into a single
product. This reduces the number of injections required to prevent some diseases.
 Eg: DTaP pro -diphtheria and tetanus toxoids / pertussis, acellular, M-M-R II-
measles virus vaccine / mumps virus vaccine / rubella virus vaccine
7) Viral vaccines
 Viral vaccines contain either inactivated viruses or attenuated (alive but not capable of
causing disease) viruses.
 Inactivated or killed viral vaccines contain viruses, which have lost their ability to
replicate and in order for it to bring about a response it contains more antigen than
live vaccines. Attenuated or live vaccines contain the live form of the virus. These
viruses are not pathogenic but are able to induce an immune response.
 Eg: hepatitis b adult vaccine, human papillomavirus vaccine, yellow fever vaccine etc