Comparing the effects of radiation-attenuated vaccine when administered either before or after praziquantel treatment in schistosoma mansoni infected balb/c mice
Schistosomal vaccine candidates such as Paramyosin and Multiple antigen epitopes (MAP) are in different stages of development and clinical trials. However, it is probable that during initial field clinical trials, some people may have been exposed to cercariae and become infected or re-infected. Among the infected, some people may have used anti schistosome drugs. Consequently, an animal model study was sought to elucidate the effects of administering a 20Krad radiation-attenuated vaccine before or after praziquantel treatment in Schistosome infected BALB/c. This vaccine model is not therapeutic but acts as both anti-worm and anti-fecundity vaccine. Mice were randomly grouped as follows: Mice in group A, were infected, treated, vaccinated and challenged; Mice in group B, were infected, vaccinated, treated and challenged; mice in group C, were vaccinated, treated and challenged; Mice in group D,: were given oral dose of praziquantel, and infected; Mice in group E, were only infected. All the mice were perfused at the end of experiment recover mature worms. Five mice from each group were assayed per sampling point. It was found out that administering the radiation-attenuated vaccine in BALB/c mice. before praziquantel treatment was preferable than when the vaccine is administered after treatment. This is because Lymphocyte proliferative responses in group B mice, were sufficient to cause effectively 'arming' of the lung, than in group A mice. Consequently, worm resistance against challenge infection in group B mice was higher (68.9%) than group A, (41%). However, mice in group .C~(control group) attained the highest worm resistance of 96.5%. The results also reveal that vaccination either before or after praziquantel treatment does not interfere with hepatic granuloma development and their modulation.
CitationMaster of Science in Parasitology
SponsorhipUniversity of Nairobi
Department of Zoology, University of Nairobi