In response to viral infection, the immune systems of mice typically produce antibodies that destroy the virus by binding to proteins on its surface  Mice infected with the herpesvirus generally develop keratitis, a degenerative disease affecting part of the eye
Since proteins on the surface of cells in this part of the eye closely resemble those on the herpesvirus surface, scientists hypothesize that these cases of keratitis are caused by antibodies to the herpesvirus
There are mice that are unable to form antibodies in response to herpes infections, and these mice contract herpes at roughly the same rate as other mice