Vaccination process

Medically screen, vaccinate, and complete documentation. Oversee the vaccination process sign the clinic record observe vaccine recipients for immediate reaction or complications. Must be a nurse, EMS personnel, or physician. 

As an alternative to centrifugation, a vibrating membrane filter is used in some appheations such as yeast processes Pichia pastoris) and vaccine processes. Diatomaceous earth (DE) filtration is another potential alternative. Figure 14.11 Ulustrates DE embedded within a filter module structure. 

Ceramic membrane systems are achieving widespread application in the place of centrifuges. These systems do not require filter aid media or a separate follow-on clarification step. Hollow-fiber crossflow modules are preferred for the separation of mammalian cells, which require particularly gentle handling. They can also be used as disposable filters for perfusion and vaccine processes. 

The different re-nutrition diets not only were able to reestablish the number of immune cells in the lamina propria of the small intestine, but also the functionality of them. Malnutrition induces impairment in the cytokine production by the intestinal immune cells, which was reverted when the re-nutrition diets were supplemented with PFM or BFS, reaching values near to those observed in the well-nourished control group (Figure 8.1). This finding is very important considering the role of cytokines in the enhancement of the immune response during a vaccination process (Rizza et al. 2002). 

In the preparation of classical killed or toxoid vaccines, simple process technology was used. With the advance of new vaccines, far more sophisticated process technologies are needed. The desire to reduce side effects of vaccination requires processes which will yield antigens of extreme purity. The new regulation in cGMP requires consistent production procedures, and global competition also demands that the most efficient process technology be appHed. 

The basic process technology in vaccine production consists of fermentation for the production of antigen, purification of antigen, and formulation of the final vaccine. In bacterial fermentation, technology is weU estabHshed. For viral vaccines, ceU culture is the standard procedure. Different variations of ceU line and process system are in use. For most of the Hve viral vaccine and other subunit vaccines, production is by direct infection of a ceU substrate with the vims. 

Development of conjugate and peptide vaccines requires the typical organic synthesis process and purification. This is a new area for vaccine technologists. Again, the main concern is to maintain the immunogenicity of the vaccine candidate during the chemical reaction and purification steps. 

In current practice the fluorescence assay is often followed by the use of hybridization techniques when more selectivity is required. We have for instance used the fluorescence techniques to obtain data on the nucleic acid content of malaria vaccine proteins produced in Escherichia coli. The rapid turnaround time of the fluorescence assay is particularly useful during the early stages of purification to determine the optimal process conditions. After the final process has been arrived at and a variety of methods used to assess the nucleic acid content (including the hybridization techniques), the fluorescence method can be developed for routine quality-control purposes. In certain cases, particularly at high protein concentrations, the dye may bind to the protein with... 

Liposomes have been widely used as model membranes and their physicochemical properties have therefore been studied extensively. More recently, they have become important tools for the study of membrane-mediated processes (e.g., membrane fusion), catalysis of reactions occurring at interfaces, and energy conversion. Besides, liposomes are currently under investigation as carrier systems for drugs and as antigen-presenting systems to be used as vaccines. 

Chemical research is driven by many goals, and it progresses in many different ways. The essential traits of a good researcher are curiosity, creativity, flexibility, and dedication. Some chemical advances come from a direct assault on a known problem. A classic example is the development of the Hall process for refining aluminum from its ores, which we describe in Chapter 21,. As a contemporary example, many scientists around the world are working at a feverish pace to develop a vaccine against the AIDS virus. 

The bacteria and bacterial components needed for the manufacture of bacterial vaccines are readily prepared in laboratory media by well-recognized fermentation methods. The end-product of the fermentation, the harvest, is processed to provide a concentrated and purified vaccine component that may be conveniently stored for long periods or even traded as an article of commerce. 

Fractionation. The process by which components are extracted firm bacterial eells or from the medium in whieh the baeteria are grown and obtained in a purified form. The polysaccharide antigens of Neisseria meningitidis are separated from the bacterial cells by treatment with hexadecyltrimethylammonium bromide and those of Streptococcus pneumoniae with ethanol. The purity of an extracted material may be improved by resolubilization in a suitable solvent and precipitation. After purification, a component may be dried to a powder, stored indefinitely and, as required, incorporated into a vaccine in precisely weighed amounts at the blending stage. 

Cell cultures provide infeeted fluids that eontain little debris and can generally be satisfactorily clarified by filtration. Beeause most viral vaccines made fiom cell cultures consist of live attenuated vims, there is no inaetivation stage in their manufacture. There are, however, two important exeeptions inaetivated poliomyelitis vims vaccine is inactivated with dilute formalin or /3-propiolaotone and rabies vaccine is inactivated with /3-propiolactone. The preparation of these inaetivated vaccines also involves a concentration stage, by adsorption and elution of the vims in the case of poliomyelitis vaccine and by ultrafiltration in the case of rabies vaceine. When processing is complete the bulk materials may be stored until needed for blending into final vaccine. Because of the lability of many vimses, however, it is necessary to store most purified materials at temperatures of-70°C. 

The single-component bacterial vaccines are listed in Table 15.1. For each vaccine, notes are provided of the basic material fkm which the vaccine is made, the salient production processes and tests for potency and for safety. The multicomponent vaccines that are made by blending together two or more of the single component vaccines are required to meet the potency and safety requirements for each of the single components that they contain. The best known of the combined bacterial vaccines is the adsorbed diphtheria, tetanus and pertussis vaccine (DTPerWac/Ads) that is used to immunize infants, and the adsorbed diphtheria and tetanus vaccine (DTWac/Ads) that is used to reinforce the immunity of school entrants. 

Vaccine Source materiai Processing Potency assay Safety tests... 

---