title: HBV vaccine efficacy and detection and genotyping of vaccineé asymptomatic breakthrough HBV infection in Egypt.
abstract: OBJECTIVE
  To evaluate the impact of mass vaccination against the hepatitis B virus (HBV) in Egypt, and to search for vaccinee asymptomatic breakthrough HBV infection and its genotype.
  
  
  METHODS
  Seven hundred serum samples from vaccinated children and adults (aged 2-47 years) were used for quantitative and qualitative detection of HBsAb by ELISA. Three hundred and sixty serum samples representing undetectable or low or high HBsAb were screened for markers of active HBV infection (HBsAg, HBcAb (IgG) and HBeAb by ELISA, plus HBsAg by AxSYM) and HBV-DNA genotyping by nested multiplex PCR and by DNA sequencing.
  
  
  RESULTS
  It was found that 65% of children aged 2-4 years, and 20.5% aged 4-13 years, as well as 45% adults were good responders to HBV vaccination mounting protective level HBsAb. Poor responders were 28%, 59.5% and 34%, and non-responders were 7%, 20% and 21% respectively, in the three studied groups. Markers of asymptomatic HBV infections were HBsAg detected by ELISA in 2.5% vs 11.39% by AxSYM. Other markers were HBcAb (IgG) in 1.38%, HBeAb in 0.83%, and HBV-DNA in 7.8%. All had HBV genotype E infection.
  
  
  CONCLUSIONS
  It is concluded that HBV vaccine is efficient in controlling HBV infection among children and adults. The vaccine breakthrough infection was by HBV genotype E. A booster dose of vaccine is recommended, probably four years after initial vaccination.
authors.affiliation: Eman AE Abushady, Microbiology department, Faculty of Medicine Nourthern Border University, Arar 1321, Saudi Arabia.
authors.forename: Eman Ae
authors.initials: EA
authors.lastname: Abushady
authors.forename: Magda Ma
authors.initials: MM
authors.lastname: Gameel
authors.forename: John D
authors.initials: JD
authors.lastname: Klena
authors.forename: Salwa F
authors.initials: SF
authors.lastname: Ahmed
authors.forename: Kouka Se
authors.initials: KS
authors.lastname: Abdel-Wahab
authors.forename: Sanya M
authors.initials: SM
authors.lastname: Fahmy