Live trachoma vaccine and topical therapy.

Abstract

It was stated (Scott, I964) that a live trachoma vaccine had no clear-cut effect in cases of severe trachoma although there were encouraging results in patients with mild trachoma and in a volunteer. This paper, which describes a further study supported by statistical analysis carried out on 553 children over a period of 5 years, confirms that no clear-cut benefit was obtained from the use of a live trachoma vaccine in cases of severe trachoma. Material and methodsA school for 300 native Bantu children aged from 7 to 15 years was selected in the Northern Transvaal where classical trachoma was known to be common. Attendance at school was not compulsory and only 193 were present at the first examination in i965 by Scott and Pienaar, who reached agreement on their findings, each using a loupe in daylight. Pannus of 2 to 3 mm. and Herbert's pits were found in 48 of the first fifty children examined, after which these signs were ignored. The upper lid was everted and three abnormal signs were commonly found.: (I) Follicles (2) Hyperaemia (3) Hyperplasia of the tarsal conjunctiva.These were not necessarily regarded as signs of trachoma but each was given a figure to represent severity as described later by the statistician. Of the I93 children, I 13 had signs of active infection, nineteen had scars in a quiet eye, and 4I had a normal tarsal conjunctiva.In the following 3 years, the new intakes of I I I, 126 and I23 children were examined and the old cases re-examined by the same two ophthalmologists. Swabs for TRIC culture were positive in 9I of 98 unselected children in I965; this high proportion of positives fell to 55, 28, and 8 per cent. in the three successive intakes although the incidence of trachoma and the average point score were much the same in each group. Cultures were done by Mrs. Cuthbertson and Miss Ryan at the South African Institute for Medical Research.Another curious feature was that a higher proportion of positive cultures came from those with lower total scores (e.g. 3, 2, or i). In each intake there were one or two carriers, i.e. patients with a normal tarsal conjunctiva who yielded TRIC agent on culture but had a total score of o.A live trachoma vaccine (E.I.D. iO-3), prepared at the South African Institute for Medical Research under the direction of Prof. J. H. S. Gear, was given by subcutaneous injection to onethird of the children selected by random numbers. Each vaccinated child was given a second dose a month later and a booster dose each subsequent year. If a patient was absent when the vaccinations took place, every effort was made to give the vaccine at the earliest opportunity and nearly all of the selected children received their quota of vaccine. There was only one case of reaction (allergic oedema). As practically every child in that area contracted trachoma by the age of I year it was decided to treat all scholars (irrespective of initial score) with I per cent. tetracycline ointment once daily during their first school year in the hope that the vaccine would prevent reinfection wh...