The current tuberculosis (TB) vaccine Mycobacterium bovis bacillus Calmette-Guerin (BCG) provides efficient protection against TB in newborns, but does not prevent the establishment of latent
TB or reactivation of pulmonary disease in adults. Current vaccine development focuses on two approaches: (1) Replacing BCG
with a more effective vaccine or (2) boosting BCG with a booster vaccine which takes advantage of BCG priming vaccination
in childhood, and which is given to increase the immune response and prolong immunity to an adult population.32,33 Several vaccines are in various stages of early clinical development. rBCG30 is a recombinant BCG vaccine (to replace GCG)
under clinical studies as a BCG replacement. It overexpresses the surface antigen Ag85B, which appears to increase immune
response to this important antigen. MVA85A is a modified vaccine virus Ankara (MVA) strain expressing antigen 85A (to boost
BCG). It induces strong immune responses, particularly in previously BCG-vaccinated individual. Ag85B-ESAT6 is made up of
two secreted antigens Ag85B and ESAT6. It has shown promise both parenterally and through the mucosal route.
New technologies include recombinant cell culture methodologies, transgenic systems to produce edible vaccines, new conjugation
methods, delivery systems free of needles, disposable manufacturing technologies and stable formulations that will enable
developing countries to transport or store the vaccines at ambient temperatures. DNA-based vaccines are cost-effective, can
be made faster, are stable at higher temperatures, can be delivered by needle free systems and highly suitable not only for
developing countries but also to respond to pandemic outbreaks or bioterrorism, given the shorter scale-up time. The development
of vaccines for Alzheimer's, cancer, drug addiction, HIV, multiple sclerosis, tropical diseases, and autoimmune disorders
such as diabetes, lupus erythematosus, and arthritis will be the future focus for the scientific community and biotechnology
companies globally. The opportunities, possibilities, and market potential are so great that many new players will enter the
field to shape the changing landscape of vaccine development.
Hank Liu, PhD, is the associate director of manufacturing sciences and technologies at Wyeth Biotech, Pearl River, NY 845.602.2043, firstname.lastname@example.org
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