RESUMEN
The cell mediated immune response to herpes simplex virus was assessed by a modification of the leukocyte migration inhibition test, developed to increase its sensitivity and correlated with the in vitro stimulation of lymphocytes. The introduction of a preincubation step allowed us to demonstrate significant inhibition of leukocyte migration in 15 out of 24 subjects susceptible to recurrent herpes labialis. This was not present in any of the 10 subjects without such infections. However lymphocytes from all 24 subjects demonstrated stimulation in response to herpes virus antigen. The degrees of lymphocyte stimulation and migration inhibition in the susceptible subjects were well correlated and do not support the suggestion that there is a focal defect in this aspect of the cell mediated immune response to herpes simplex virus in those patients.