Studies on trachoma. 5. Complement-fixation tests in human volunteers

Complement-fixation tests carried out on serial serum samples from human volunteers indicate that group-specific antibodies develop after experimental inoculation of trachoma virus and inclusion conjunctivitis virus. The results obtained with antigens prepared from four trachoma virus strains isolated in Tunisia and one strain from Japan and with an ornithosis antigen suggest that there may be antigenic differences among trachoma virus strains and that the use of homologous antigens will therefore give the best results.