Schistosomiasis vaccines.
While there are many challenges in vaccine development, none is greater than that of developing vaccines against large metazoan parasites such as schistosomes, the parasitic worms that are responsible for schistosomiasis. Initial optimism stemming from the identification of the first vaccine candidate antigens that gave protection in animals has been dashed by the failure, as yet, of any of the vaccine candidate antigens to enter Phase III clinical trials. Now, despite an improved understanding of the biology of the parasites and of the immune responses they stimulate in naturally exposed populations, the vaccine effort is stalled. The control effort has switched heavily in favour of the wider use of conventional chemotherapy with praziquantel, which is now affordable by all but the poorest countries. Disagreements among researchers in the schistosome field as to whether or not a vaccine is needed have not helped convince funding agencies that schistosomiasis vaccines, rather than drugs, should be a priority. With the schistosome genome projects at an advanced stage plus the power of the proteomics, perhaps it is still too early to call time on schistosome vaccine development.
Hagan
Paul
P
Division of Infection and Immunity, Joseph Black Building (B4-09d), Institute of Biomedical and Life Sciences, University of Glasgow, G12 8QQ UK. P.Hagan@bio.gla.ac.uk
Sharaf
Osama
O
D000818:Animals; D000871:Anthelmintics; D000947:Antigens, Helminth; D002986:Clinical Trials as Topic; D003131:Combined Modality Therapy; D006801:Humans; D011223:Praziquantel / Q000627:therapeutic use; D016052:Protozoan Vaccines; D012552:Schistosomiasis / Q000453:epidemiology / Q000517:prevention & control*
D000871:Anthelmintics; D000947:Antigens, Helminth; D016052:Protozoan Vaccines; D011223:Praziquantel