Brief Article
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World J Hepatol. Jun 27, 2011; 3(6): 147-156
Published online Jun 27, 2011. doi: 10.4254/wjh.v3.i6.147
HBV vaccine efficacy and detection and genotyping of vaccineé asymptomatic breakthrough HBV infection in Egypt
Eman AE Abushady, Magda MA Gameel, John D Klena, Salwa F Ahmed, Kouka SE Abdel-Wahab, Sanya M Fahmy
Eman AE Abushady, Microbiology department, Faculty of Medicine Nourthern Border University, Arar 1321, Saudi Arabia
Magda MA Gameel, Kouka Abdelwahab, Microbiology department, Faculty of Medicine, AL-Azhar University, Cairo R695-11651, Egypt
John D Klena, Salwa F Ahmed, Molecular Epidemiology unit, Clinical Trials Program, NAMRU-3, Cairo 11157, Egypt
Sanya M Fahmy, Pediatric department, Faculty of Medicine, AL-Azhar University, Cairo R695-11651, Egypt
Author contributions: Abushady EAE was the principal investigator responsible for the design of study, supervision, manuscript writing, acquisition of funding; Gameel MMA did the PCR and multiplex PCR practical work, shared in paper revision and correction; Klena JD provided us with technology and materials needed for confirmation of the multiplex PCR results and sequencing of the obtained genome, interpretated and analyzed the data, and shared in paper revision and correction; Ahmed SF confirmed the multiplex PCR results and sequenced the obtained genome and shared in interpretation of the sequencing data; Fahmy SM collected the serum samples done under her supervision; Abdel-Wahab KSE participated in paper revision and correction.
Correspondence to: Eman AE Abushady, Professor, Microbiology Department, Faculty of Medicine, Nourthern Border University, Arar-1321, Saudi Arabia.
Telephone: +966-540489688 Fax: +966-46640705
Received: October 20, 2010
Revised: May 15, 2011
Accepted: May 22, 2011
Published online: June 27, 2011

AIM: 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.

CONCLUSION: 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.

Keywords: HBV vaccine evaluation, Egyptain children, Adults, Genotype E vaccine escape HBV