Vaccination of mice with a 30 kDaSchistosomaantigen with and without human adjuvant induces high protection againstS. mansoniinfection

Myrrh and artesunate modulate some Th1 and Th2 cytokines secretion in Schistosoma mansoni infected mice

The effects of artesunate and myrrh on S. mansoni infection and the levels of some Th1 and Th2 cytokines were evaluated in the present study. Six weeks after infection, a group of mice was treated with 4 mg/kg of artesunate and other group was treated with 10 mg/kg of myrrh for 3 successive days. Worm burden was reduced with a percentage of 53.7% and 58.78% after treatment with myrrh and artesunate respectively as well as the levels of IgG antibodies were significantly reduced compared with infected group. No obvious changes were observed in the level of interferon γ after treatment. After treatment with artesunate, interleukin 2 (IL-2) level was significantly decreased, while no significant difference was observed in myrrh-treated group compared with the infected group. On the other hand, the level of IL-10 was not significantly decreased after treatment with artesunate, but it was significantly increased after treatment with myrrh. However, IL-12 levels were significantly decreased after treatment with artesunate. The results demonstrated that, artesunate or myrrh treatment could give a level of protection against S. mansoni infection and modulate the levels of some Th1 and Th2 cytokines in mice infected with S. mansoni.

Schistosomiasis in Egypt: A never-ending story?

Schistosomiasis has plagued the Egyptian population since the antiquity. The disease is still a public health problem in Egypt, despite the tendency of being overlooked. In the first part of this review, the past and current trends of schistosomiasis in Egypt are reviewed, including history, epidemiology, morbidity, therapy, and control of the disease. Most of these aspects are more or less relevant to other schistosome-endemic regions all over the world. As only one drug is currently available for individual treatment and preventive mass chemotherapy, the quest for complementary measures is urgently warranted. Indeed, one promising approach is the discovery of a vaccine. Herein, we point out the efforts of the Egyptian scientists to develop an efficacious and affordable vaccine against schistosomiasis - a step forward in the battle of elimination of Schistosoma infection. Based on the candidate vaccine antigens, four types of vaccine formulations are discussed: purified antigen vaccines, DNA constructs, attenuated cercariae, and excretory-secretory antigen vaccines. Finally, this review provides insights into this ancient seemingly long-lasting parasitic disease.

Vaccine-linked chemotherapy: can schistosomiasis control benefit from an integrated approach?

The present strong emphasis on gross organ pathology (liver, kidneys, bladder) in schistosomiasis needs to be replaced with a more balanced view of the disease that also takes into account systemic symptoms that are less easy to assess, such as retarded growth, cognitive development and the effect of continuing low-level blood loss. Access to better estimates of disease burdens, morbidity and mortality is delivering results that bring into question the wisdom of downgrading the impact of the disease. In this scenario, the simplistic approach of exclusive drug treatment might not be sufficient and, in the worst-case scenario, might even exacerbate pathology. To meet this challenge, the repositioning of vaccines within the totality of disease control through the combined use of chemotherapy and vaccination is recommended as the basis for a novel, more-versatile approach to control. Studies on human correlate responses in endemic areas have opened the way to assess the protective value of specific antigens through the cytokine responses and antibodies they elicit. Moreover, vaccine formulations based on novel adjuvants could improve the final outcome through selective manipulation of the immune response. Thus, the tools of vaccine-linked chemotherapy are in principle already available and could shortly be put to the test in clinical trials.