Trachoma Viruses Isolated in the United States. 4. Infectivity and Immunogenicity for Monkeys

Abstract

Three strains of trachoma virus and one of inclusion conjunctivitis isolated in the United States gave reproducible disease upon inoculation into the eyes of rhesus or cynomolgus monkeys. Among several clinical criteria, follicle scores were most suitable for evaluating quantitative differences in the disease produced by various strains. The presence of characteristic cytoplasmic inclusion bodies in conjunctival scrapings served as an additional criterion of infection. Significant differences were demonstrated in the infectivity of 2 virus strains for the monkey eye. Repeated eye infection failed to modify the response to reinfection. Attempted immunization by the parenteral administration of a crude yolk sac suspension of live virus in large quantities significantly diminished disease from subsequent challenge infection, but failed to induce solid immunity.