Vaccine Design and Drug Delivery Technology

• Immunotherapy and Vaccines
• Novel Vaccine Drug Delivery Systems

The term “vaccine” was coined by Louis Pasteur and derived from “Vacca”, meaning cow the term devised by Edward Jenner to denote cowpox. A vaccine is defined as a biological preparation that provides active acquired immunity to a particular disease and typically contains an agent that resembles a disease-causing microorganism and is often made from the exhaust or killed forms of the microbe, its toxins, or one of its surface proteins.

Vaccines have two major effects:

a) Vaccines protect individuals against disease.

b) If there are sufficient immune individuals in populations, the transmission of the infection is prevented. This is known as herd immunity.

Vaccine Design mainly includes the Production of vaccines and has several stages.

Firstly, the antigen itself is generated and Viruses are grown either on primary cells such as chicken eggs (e.g., for influenza), or on continuous cell lines such as cultured human cells (e.g., for hepatitis A). Bacteria are grown in bioreactors (e.g., haemophilic influenza type B).

Alternatively, a recombinant protein will be derived from the viruses or bacteria can be generated in yeast, bacteria, or cell cultures.

Strategies in vaccine design include:

• Manipulate Cytokine environment
• Use appropriate antigen-presenting cells
• Use immunogenic portions of the antigen
• Engineer the antigen to optimize immunity
• Make “self” more immunogenic.

Vaccine drug delivery system is the preparations given to patients to evoke immune responses that leading to the production of antibodies or cell-mediated responses that will help in combating infectious agents or non-infectious conditions such as malignancies.

The three categories of Vaccine delivery system include:

• Adjuvants and formulations
• Antigen vectors, including live attenuated micro-organisms and synthetic vectors
• Novel devices for vaccine administration.