Development of Immunity by Repeated Infection of Trachoma

It has been accepted in general that there is a relative immunity in trachoma associated with persistence of the infection but that there is no permanent immunity. Reinfection experiments in man as well as in monkeys have resulted in an onset of trachoma without exception.^1-3 Superinoculation experiments, however, have not always resulted in a provocation of the symptoms.⁴ Vaccine has been tried in the treatment of trachoma without benefit.⁵ Some serological activity has been demonstrated in trachoma patients.^6,7 But γ-globulin in the patient's serum⁸ and in the infected conjunctival tissue⁹ did not show significant increase. A toxin-like substance of trachoma virus and the allergic nature of it have been demonstrated experimentally.¹⁰ Some allergic tissue reaction was demonstrated histologically in the trachoma-infected tissue.¹¹ Some other workers still claimed the presence of immunity in trachoma, either of congenital or of acquired origin.¹²

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