Immunity to chlamydial infections of the eye. II. Studies of passively transferred serum antibody in resistance to infection with guinea pig inclusion conjunctivitis.

Conjunctival infection of guinea pigs by the chlamydial agent of guinea pig inclusion conjunctivitis confers immunity. However, the mechanism of resistance to this intracellular pathogen is not yet defined. In the study reported here, serum immunoglobulin was passively transferred with resultant titers in excess of those known to be associated with immunity. Nonetheless, when the passive transfer recipients were challenged, they acquired infection which was neither delayed nor attenuated. Eye secretion antibody titers appeared and increased only after 11 days of infection in both passive transfer recipients and control groups, suggesting but not proving de novo local synthesis of secretory antibody. This study suggests that cellular or secretory immune mechanisms may predominate in resistance to this infection.