Immunocompetence is the ability of the body to produce a normal immune response (i.e., antibody production and/or cell-mediated immunity) following exposure to an antigen, which might be an actual virus itself or an immunization shot. Immunocompetence is the opposite of immunodeficiency or immuno-incompetent or immuno-compromised. Several examples would be a newborn that does not yet have a fully functioning immune system but may have maternally transmitted antibody - immunodeficient; A late stage aids patient with a failed or failing immune system - immuno-incompetent; or a transplant reciepient taking medication so their body will not reject the donated organ - immunocompomised. There may be cases of overlap but these terms are all indicators of non fully functioning immune system.
In reference to lymphocytes, immunocompetence means that a B cell or T cell is mature and can recognize antigens and allow a person to mount an immune response.
