Hepatitis b virus vaccine response in children 15–19 years old

Abstract

To determine Hepatitis B virus vaccine response in vaccinated children 15–19 years old. Three hundred children were vaccinated after an informed consent and after tests for Hepatitis B virus (HBV) markers (HBsAg, anti-HBc and anti-HBs) during 1999–2000 in program INTERREG II of European Community (EC). All of them were negative before vaccination. The children were vaccinated by the classic (months 0, 1 and 6) schedule (XI, XII 1999—V 2000). Recombinant Hepatitis B vaccine ENGERIX™ (SmithKline Beecham Biologicals S.A.—Belgium) was given as 20 mcg intramuscular injections via the deltoid muscle. Seroconversion was defined in 280 of them on days 30 or more after the last immunization as the presence of hepatitis B surface antibody concentration >= 10 IU/L in serum samples, while concentrations of > =100 IU/L were considered to be seroprotec-tive. The serological hepatitis B surface antibody titration was carried out using a commercial ELISA kits (DiaSorin—ETI—AB—AUK—3—Italy) and DiaSorin automated system and software. After three doses of vaccine, anti HBs concentration reached levels >=10 IU/L was determined in 96.3% of children. Protective levels >= 100 IU/L was determined in 86% of them. The initial immune response to hepatitis B vaccine following the basic immunization series is an important determinant of the duration of immunity. Our data indicate that performed Hepatitis B vaccine induced good immune response of the children vaccinated, but 3.6% of them failed to produce any antibody response and 10.3% - failed to produce protective antibody levels. For the last children a booster doses of vaccine must be applicated. © 2005 Taylor and Francis Group, LLC.