Immunity in Schistosomiasis

Schistosoma mansoni: antigenic community between schistosomula surface and adult worm incubation products as a support for concomitant immunity

“…The concept of concomitant immunity was first introduced [9] in a situation in which hosts develop resistance against a challenge infection but cannot rid themselves of the established adult worm population. The slow development of immunity in infected hosts suggested that adult worms could provide the major immunogenic stimulus and direct evidence of this was given by the same authors who showed that monkeys could be protected from infection by cercariae following transfer of adult worms [I].…”

Vaccination with antioxidant enzymes confers protective immunity against challenge infection with Schistosoma mansoni

“…1 and LoVerde 1998 for review). The second paradigm is that the adult parasite seems to be able to evade immune elimination through the evolution of several defense mechanisms (Smithers & Terry 1969, Smithers 1982, Maizels et al 1993, Pearce & Sher 1987, LoVerde 1998. We postulate that in order to survive in the portal circulation of the liver, the adult worm stage has evolved a defense against the immune attack that involves the expression of antioxidant enzymes (Fig.…”

“…However, two paradigms have emerged from the various immune models of schistosomiasis studied to date. The first paradigm is that the larval stage (schistosomulum) is the most susceptible and the target of immune elimination (Smithers 1982, Smithers &Terry 1969, LoVerde 1998. Evidence indicates that larval parasite killing primarily involves a cellular response that includes monocytes, macrophages, eosinophils, and platelets ( Fig.…”

Schistosome vaccines: a critical appraisal

“…The concept of concomitant immunity, introduced by Smithers and Terry (1969), dominated thinking about schistosome immunology and vaccine research for two decades. These researchers reported that when the rhesus macaque (Macaca mulatta) was given an infection, the primary worm burden persisted but the animals were resistant to a secondary cercarial challenge.…”