Schistosoma mansoni: is acquired immunity induced by highly x-irradiated cercariae dependent on the size of the challenging dose
A high degree of immunity, as shown by a 91% reduction of the number of worms recovered was found in five groups of mice that were immunized five times with highly X-irradiated cercariae and then challenged with 10, 20, 50, 100, or 500 normal Schistosoma mansoni cercariae. The results indicated that there were no significant differences in worm reduction in immunized mice challenged with different numbers of cercariae; consequently the immunity induced by this immunization method did not appear to be challenge-dose-dependent. However, the results also showed that when immunized mice were challenged with 500, 100, 50, 20, and 10 cercariae, 0, 13, 26, 56, and 68%, respectively, of the experimental animals were free of worms. Thus, the percentage of worm-negative cases increased as the number of challenge cercariae decreased. When viewed in this manner, the acquired immunity may be considered challenge-dose-dependent as well. If this method of vaccination is used for schistosomiasis control, we may anticipate that in both hypo- and hyperendemic areas, the intensity of infection and the severity of the disease will be reduced owing to a reduction in worms burdens, and in hypoendemic areas, there will be a number of worm-free cases.
- Research Organization:
- Department of Preventive Medicine and Environmental Health, University of Iowa, Iowa City
- OSTI ID:
- 6782667
- Journal Information:
- J. Parasitol.; (United States), Vol. 68:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SCHISTOSOMA
BIOLOGICAL RADIATION EFFECTS
SCHISTOSOMIASIS
VACCINES
DOSE-RESPONSE RELATIONSHIPS
IMMUNITY
INOCULATION
MICE
PREVENTIVE MEDICINE
X RADIATION
ANIMALS
BIOLOGICAL EFFECTS
DISEASES
ELECTROMAGNETIC RADIATION
HELMINTHS
INFECTIOUS DISEASES
IONIZING RADIATIONS
MAMMALS
MEDICINE
PARASITIC DISEASES
PLATYHELMINTHS
RADIATION EFFECTS
RADIATIONS
RODENTS
TREMATODES
VERTEBRATES
560134* - Radiation Effects on Microorganisms- Vaccine Preparation & Other Applications- (-1987)