Vaccines

You are asked to research a case where the development of an effective vaccine has proved difficult or impossible. Go to PubMed and find at least one peer-reviewed article to summarize and discuss. Be sure to include: 1) a bit about the disease and the pathogen targeted; and 2) why the development of an effective vaccine has been difficult or impossible. For example: why is it that the flu vaccine reduces the risk of illness by 40 – 60% and not more? Why has it been difficult to develop a vaccine against the malaria parasite?
Your topic must focus on a vaccine that will prevent infectious disease (influenza, mumps, malaria, etc. not Alzheimer’s disease).

Please be sure to mention:

The pathogen targeted
The disease(s) implicated
If a vaccine has been developed or is being developed, what kind of vaccine is it (live attenuated, toxoid, etc.)? Does it contain an adjuvant? Are boosters required? Any safety issues?
Why the development of an effective vacciawzne has been difficult or impossible