There was studied the effect of hepatitis A on the state of active artificial antitoxic immunity to diphtheria in previously vaccinated children. It was found reduction of antibody titers to diphtheria during the full disease course compared with healthy children of all age groups. In particular it is proved that the presence of deprotected titers in children suffering from viral hepatitis A aged 7–14 years were observed during hospitalization: the proportion of patients with deprotected antibody titers — 41.4%. The identified level of active artificial diphtheria immunity of hepatitis A course is characterized by dynamic changes, depending on the age of children and primary state of their immune protection.
