Plasmodium falciparum...
the parasite that never gives up

What can be so small you need a microscope to see it, yet still kills as many as 300 to 500 million people a year?

What has become so widely resistant to past vaccines, that no true vaccine has yet been found?

What is considered a parasite, carried by mosquitoes, and finds human vertebrate hosts?

What is currently endemic in tropical and subtropical climates, but is spreading to other countries due to increased international travel, changes in temperatures due to global warming, and an increase in the number of vectors?

The answer: Plasmodium falciparum
and the disease it causes, Malaria.

Plasmodium falciparum is both the most deadly and most researched species of malaria (MVI fact sheet). Four forms of malaria Plasmodium exist: Plasmodium falciparum, vivax, ovale, and malariae. The majority of the research conducted is to find a vaccine or treatment for the disease. In an article by Thomas Smith he states, "Despite considerable efforts ...and millions of dollars spent, there is still no registered vaccine against Plasmodium falciparum malaria." Some believe that due to the ineffectiveness of the past, any vaccine found will most likely not become completely effective (Smith). Others remain hopeful citing the fact that the species complex life cycle offers numerous options for vaccines and treatments, as well as the proof that partial immunity does occur in endemic areas in some people (Francis). 

However, since both morbidity and mortality rates are so high in endemic areas, finding a vaccine is incredibly important (Smith). "Untreated, up to 20% of people infected with falciparum malaria will die." (MVI).