Oral and parotid secretion specimens were collected three times each week and serum was collected at monthly intervals from 10 healthy adult volunteers for 5 months. Herpes simplex virus was isolated in rabbit kidney tissue cultures 22 times from oral secretions (3.6%), but all parotid saliva specimens were negative for virus. Eight individuals shed herpesvirus, and virus was isolated from one individual seven times. Seven of the eight volunteers who shed herpesvirus experienced 14 episodes of herpes labialis. Seven of 29 (24.1%) specimens of oral secretion obtained while a lesion was present were positive for herpesvirus, whereas only 11 of 494 (2.2%) obtained more than 7 days after a lesion occurred were positive.

Serum-neutralizing antibody titers ranged from 1:8 to 1:1024 and remained constant irrespective of whether herpesvirus was isolated or herpetic lesions occurred. Neither the frequency of virus isolations nor the number of herpetic lesions were related to the level of serum-neutralizing antibody. Antibody activity was not detected in pooled, concentrated specimens of parotid saliva, and only 6 of 60 concentrated specimens of oral secretion contained low titers of neutralizing activity despite good levels of IgA. Sucrose density gradient ultracentrifugation studies showed that this antibody activity was associated with 7S IgG rather than with 11S IgA.

These findings suggest that herpesvirus chronically infects a site with access to the mouth, but that the parotid glands are not such a site; that the magnitude of serum antibody does not influence shedding of herpesvirus or the occurrence of herptic lesions; and that local IgA antibody does not appear to play a role in recurrent herpes labialis.