biostudies-literatureUnknown10Steiner M<h4>Background</h4>Few studies have assessed long term persisting immunity against hepatitis B virus (HBV) in children vaccinated during infancy with combined vaccines containing recombinant HBV surface antigen (HBs). We assessed antibody persistence and immune memory in children 4-5 years of age, previously vaccinated with four doses of combined hexavalent DTPa-HBV-IPV/Hib vaccine (Infanrix hexa).<h4>Methods</h4>Immune memory was assessed in 301 children through administration of a challenge dose of monovalent HBV vaccine.<h4>Results</h4>At 4-5 years of age, 85.3% of subjects had persisting anti-HBs antibody concentrations >or= 10 mIU/mL, rising to 98.6% after the HBV challenge dose. All but 12 subjects (95.8%) achieved post-challenge anti-HBs concentrations >or= 100 mIU/mL. The post-challenge anti-HBs GMC rose by 100-fold compared to pre-challenge concentrations. An anamnestic response to the HBV vaccine challenge was observed in 96.8% of subjects, including 17/21 (81.0%) of children with initially undetectable antibodies (<3.3 mIU/mL). All but 4 of 42 subjects (90.5%) with anti-HBs antibodies <10 mIU/mL prior to the challenge dose, achieved seroprotective levels afterwards. A 4-fold rise in antibody concentration after the challenge dose was observed in 259/264 (98.1%) of initially seropositive subjects. The magnitude of the post-challenge responses was proportional to pre-challenge anti-HBs levels. No serious adverse events were reported during the study.<h4>Conclusion</h4>The combined DTPa-HBV-IPV/Hib vaccine induced lasting immune memory against hepatitis B. Long term protection afforded by DTPa-HBV-IPV/Hib is likely to be similar to that observed following priming with monovalent HBV vaccines.<h4>Trial registration</h4>http://www.clinicaltrials.gov 106789 NCT00411697.BMC infectious diseases9https://www.ebi.ac.uk/biostudies/studies/S-EPMC2821389biostudies-literatureLasting immune memory against hepatitis B in children after primary immunization with 4 doses of DTPa-HBV-IPV/Hib in the first and 2nd year of life.PMC2821389Gartner BVan Der Meeren OSchuster VSteiner MRamakrishnan GJacquet JMfalseLasting immune memory against hepatitis B in children after primary immunization with 4 doses of DTPa-HBV-IPV/Hib in the first and 2nd year of life.<h4>Background</h4>Few studies have assessed long term persisting immunity against hepatitis B virus (HBV) in children vaccinated during infancy with combined vaccines containing recombinant HBV surface antigen (HBs). We assessed antibody persistence and immune memory in children 4-5 years of age, previously vaccinated with four doses of combined hexavalent DTPa-HBV-IPV/Hib vaccine (Infanrix hexa).<h4>Methods</h4>Immune memory was assessed in 301 children through administration of a challenge dose of monovalent HBV vaccine.<h4>Results</h4>At 4-5 years of age, 85.3% of subjects had persisting anti-HBs antibody concentrations >or= 10 mIU/mL, rising to 98.6% after the HBV challenge dose. All but 12 subjects (95.8%) achieved post-challenge anti-HBs concentrations >or= 100 mIU/mL. The post-challenge anti-HBs GMC rose by 100-fold compared to pre-challenge concentrations. An anamnestic response to the HBV vaccine challenge was observed in 96.8% of subjects, including 17/21 (81.0%) of children with initially undetectable antibodies (<3.3 mIU/mL). All but 4 of 42 subjects (90.5%) with anti-HBs antibodies <10 mIU/mL prior to the challenge dose, achieved seroprotective levels afterwards. A 4-fold rise in antibody concentration after the challenge dose was observed in 259/264 (98.1%) of initially seropositive subjects. The magnitude of the post-challenge responses was proportional to pre-challenge anti-HBs levels. No serious adverse events were reported during the study.<h4>Conclusion</h4>The combined DTPa-HBV-IPV/Hib vaccine induced lasting immune memory against hepatitis B. Long term protection afforded by DTPa-HBV-IPV/Hib is likely to be similar to that observed following priming with monovalent HBV vaccines.<h4>Trial registration</h4>http://www.clinicaltrials.gov 106789 NCT00411697.2010-01-01T00:00:00Z2010 Jan2024-11-15T06:39:35.347Z2019-03-27T00:28:35ZS-EPMC28213892007887610.1186/1471-2334-10-9