Biomedical Engineering Reference
In-Depth Information
Cell harvesting, followed by
homogenization and
clarification
Large scale (600L)
fermentation of recombinant
S
.
cerevisiae
Affinity chromatography
Hydrophobic interaction chromatography
Formaldehyde treatment
Addition of adjuvant (Al(OH)
3
)
and preservative (Thimerosal)
Sterile filtration and aseptic filling
into final product container
Figure 13.10
Overview of the production of recombinant HBsAg vaccine (Recombivax HB; Merck). A single
dose of the product generally contains 10
ยต
g of the antigen
generally required to elicit and immunological response, some carriers are inappropriate due to
their ability to elicit a hypersensitive reaction, particularly when repeat injections are undertaken.
Such diffi culties can be avoided by judicious choice of carrier. Often, a carrier normally used
for vaccination itself is used. For example, tetanus toxoid has been used as a carrier for peptides
derived from infl uenza haemaglutanin and
Plasmodium falciparum
.
13.4.4 Vaccine vectors
An alternative approach to the development of novel vaccine products entails the use of live vaccine
vectors. The strategy followed involves incorporation of a gene/cDNA coding for a pathogen-derived
antigen into a non-pathogenic species. If the resultant recombinant vector expresses the gene product
on its surface, then it may be used to immunize against the pathogen of interest (Figure 13.12).
Most vaccine vectors developed to date are viral based, with poxviruses (as well as picorna
viruses and adenoviruses) being used most. In general, such recombinant viral vectors elicit both
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