Subnormal and waning immunity to tetanus toxoid in previously vaccinated HIV-infected children and response to booster doses of the vaccine.

Little is known regarding waning immunity to tetanus toxoid (TT) in HIV-infected children and the need for booster doses before the recommended interval of 5-10 years. Anti-tetanus antibodies were assessed by ELISA in 24 HIV-infected and 24 control children. A protective level (>0.