Vaccines traditional

Although the term is somewhat uncommon for vaccines, traditional investigations about their mode of action by assessing the type and duration of protective immune mechanisms under various conditions are based on a very similar approach. 

The distinctions between vaccines and pharmaceuticals in terms of their underlying science and their R D processes can be murky, particularly as more therapeutic pharmaceuticals rely on biotechnological techniques to replicate substances naturally found in living organisms as many vaccines traditionally have done. 

Vaccination to induce an adaptive immune response is expected for a broad range of infectious diseases and cancers. Traditional vaccines are mainly composed of live attenuated viruses, whole inactivated pathogens, or inactivated bacterial toxins. In general, these approaches have been successful for developing vaccines that can induce an immune response based on antigen-specific antibody and cytotoxic T lymphocyte (CTL) responses, which kill host cells infected with intracellular organisms (Fig. 1) [1,2], One of the most important current issues in vaccinology is the need for new adjuvants (immunostimulants) and delivery systems. Many of the vaccines currently in development are based on purified subunits, recombinant... 

For the purposes of this discussion, the term traditional refers to those vaccines whose development predated the advent of recombinant DNA technology. Approximately 30 such vaccines... 

Table 13.6 Some traditional vaccine preparations that find medical application. In addition to being marketed individually, a number of such products are also marketed as combination vaccines. Examples include diphtheria, tetanus and pertussis vaccines and measles, mumps and rubella vaccines...

Regulatory guidance for the conduct of clinical trials on vaccines is specific. Traditional phase I trials in normal volunteers are not conducted. Rather, all trials assess not only safety but also efficacy (or at least immunogenicity). Trials may well be challenge trials, that is, after immunization subjects are purposely challenged with exposure to the infective agent of concern. 

Describe the different types of vaccines give examples of those produced by traditional methods and current techniques. Explain how the use of adjuvants can help to improve the efficacy of vaccines. 

The WHO met in January 2005 and set up guidelines for plant-derived vaccines, including the disposal of waste materials. The meeting concluded that the present guidelines on traditional vaccine development and evaluation can be applied to edible vaccines. 

New vaccines have to be evalnated regarding their immunostimnlatory and immunosuppressing properties (1). When traditional methodologies are nsed, this evaluation is demanding and yet incomplete, with only a few biological responses measured. Consequently, the development and introdnction of new powerful techniques that allow rapid toxicological and immnnological evalnation are essential (2). 

The clinical significance of DNA-based contaminants in biopharmaceutical products remains unclear. Many traditional biological-based preparations, especially those such as vaccines produced in cell culture systems, have been found to consistently contain host cell-derived DNA. No adverse clinical effects related to the presence of such DNA has been reported. 

---