الفهرس 
Classical types of vaccinesOnly 14 pages are availabe for public view
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Abstract
The large burden of communicable diseases and the role of vaccines in the change of this large burden stimulated researchers to think of new vaccines. New approaches in the field of vaccination are being tried now to develop new successful vaccines. New types of adjuvants for increasing potency of vaccines, new types of vaccines such as recombinant live vector vaccines and DNA vaccines are being developed. Therapeutic vaccines for chronic vial infections, cancer, diabetes, and hypertension are being studied hard with the hope of developing successful vaccines for them soon. Yet, there are many challenges facing the development and use of these new vaccines. Antigenic variation and diversity of microbes, lack of correlates of protection for some vaccines, and public resistance to vaccination all represent major challenges that need to be overcome. Also, there are some obstacles delaying the development of successful cancer vaccines like finding the appropriate antigen, finding correlates of protection, and the genetic instability of cancer cells. In addition to these challenges, safety of vaccines, ethics related to vaccine trials and economics are major obstacles facing researches and workers in the field of vaccination. These challenges are obvious when talking about vaccines for tuberculosis, malaria, and AIDS.