The Effect of Trachoma Virus Vaccine on the Course of Experimental Trachoma Infection in Blind Human Volunteers

Abstract

The TRIC-Taiwan-1-1958 strain of elementary body virus isolated from a trachoma patient on Taiwan has been proven capable of reproducing trachoma by experimental inoculation of six human volunteers. Virus material derived from the seventh passage in embryonated hen eggs caused the clinical picture of trachoma in every inoculation, even at the dilution of 10–4 of infected yolk sacs (approximately 1 EID50). There was a similar clinical picture with each inoculation beginning with an acute follicular conjunctivitis which progressed for 4 months and then persisted with chronic changes until 9 months when treatment was begun. The illness was generally more acute than would be expected in natural trachoma. That trachoma was reproduced was shown by the involvement of the cornea with epithelial keratitis and pannus, and by the occurrence of gelatinous follicles and eventual cicatrization of the conjunctiva. These clinical findings were supported by repeated demonstrations of typical inclusion bodies of Halberstaedter-Prowazek from conjunctival and even corneal cells, by repeated reisolation of elementary body virus in egg yolk sacs, and by the development of complement-fixing antibody with a "specific" trachoma antigen in each volunteer. Control inoculations with adenovirus type 4 and normal yolk sac showed different clinical and laboratory findings. Experimental trachoma vaccine was given to three of the volunteers to study its effect on the course of illness. An antibody response to the vaccine was demonstrated and there was a modification of disease in the volunteers receiving vaccine. While the three volunteers who received placebo each developed cross-infection of their uninoculated eye and had an acute reactivation of the bilateral disease after 1 to 2 months of antibiotic eye ointment therapy, the vaccinated volunteers remained free of infection in uninoculated eyes and showed no relapse after ointment therapy. Treatment with sulfamethoxypyridazine, a sulfa drug with prolonged action, proved to be an effective and relatively simple method of therapy for experimental trachoma.

Disease Outcome Subsequent to Primary and Secondary Urogenital Infection with Murine or Human Biovars ofChlamydia trachomatis

“…This theory is supported by experimental human conjunctivitis studies (7), previous human vaccine trials (6,18), nonhuman primate models (10), and in vitro antibody neutralization experiments (1,2,17). However, using a common murine model, we have previously found that primary infection with the mouse pneumonitis biovar of C. trachomatis (MoPn) not only yielded protection against homotypic MoPn challenge but also provided significant protection against heterotypic challenge with either human serovar E or L2 (12).…”

REVIEW ARTICLE: Chlamydia trachomatis, a Hidden Epidemic: Effects on Female Reproduction and Options for Treatment

“…Very early studies in humans indicated that individuals that had had previous ocular infections who were then immunized with a killed whole cell vaccine developed enhanced pathology of the eye upon re-exposure, compared to those who were not immunized. 91 This occurrence was thought to be linked to the high homology seen between cHSP-60 and self-HSP-60, contributing to autoimmunity and pathology development. Because of this, investigations using whole cell vaccines were not continued.…”

Lids, Lacrimal Apparatus, and Conjunctiva

“…Sulfamethoxypyradazine, a drug with pro¬ longed action, proved very effective against Taiwan-1-1958 strain experimental tracho¬ ma. 70 Repository acetyl sulfamethoxypyrada¬ zine, (Acetyl Lederkyn), when given intra¬ muscularly at weekly intervals for four injections, cured both experimentally induced and naturally occurring human trachoma without other concurrent therapy.71 This suggested a more positive means of insuring mass therapy in underdeveloped rural areas where self therapy with topical and oral sulfonamides has repeatedly failed.…”