Long term vaccine efficacy of hepatitis B vaccination of Keneba - Manduar residents

Lead Research Organisation: MRC Unit, The Gambia

Abstract

A long standing cohort of children vaccinated against hepatitis (HBV) has been followed up to determine the duration of protective proteins (antibody) responses induced by infant vaccination, and to determine vaccine efficacy against infection and against carriage. Another survey round to study long term efficacy of HBV vaccination is now due. Concurrently carriers of HBV have also been regularly followed up. Primary aims of this study are: 1) to assess vaccine efficacy 2) to assess the persistence of vaccine induced antibody levels related to time since vaccination and to peak antibody levels; 3) to explore the spatial relationship between the pressure of infection in a household (by assessing duration of residence with a chronic carrier) and clustering of break through infection; and 4) to explore the genetic determinants of immune responses in relation to antibody responses and to breakthrough infection.

Technical Summary

Baseline surveys of Hepatitis B virus (HBV) infection among the population of Keneba, Manduar and Kantong Kunda were completed in 1974, 1980 and 1984. In 1984, all non-immune children under the age of 5 years were vaccinated against HBV, and since then all children born in the villages have been vaccinated and their data entered into a database, which now contains details on over 2000 individuals. This long standing cohort of HBV vaccinated children has since been followed up in 1989, 1993, and 1998 to determine the duration of protective antibody responses induced by infant vaccination, and to determine vaccine efficacy against infection and against carriage. Another survey round to study long term efficacy of HBV vaccination is now due. Concurrently carriers of HBV have also been regularly followed up. Primary aims of this study are: 1) to assess vaccine efficacy against break through infection (anti-Bc present) and against chronic carriage; 2) to assess the persistence of vaccine induced antibody levels (anti-HBs) related to time since vaccination and to peak antibody levels; 3) to explore the spatial relationship between the pressure of infection in a household (by assessing duration of residence with a chronic carrier) and clustering of break through infection; and 4) to explore the genetic determinants of immune responses in relation to antibody responses and to breakthrough infection.
 
Title Access programe for capturing of HBV serology data 
Description An access data base was developed to capture data from ELISA plate readers of HBV serology results. This then removed the data entry step and thus remove transcription error. 
Type Of Material Database/Collection of Data/Biological Samples 
Year Produced 2007 
Provided To Others? Yes  
Impact Data entry is faster and the time between laboratory tests are performed to when they are acvailable for analysis is shortened significantly. 
 
Title qPCR assay for HBV DNA quantification 
Description A simple PCR based assay was developed to measure HBV DNA in serum of HBV chronic carriers. 
Type Of Material Technology assay or reagent 
Year Produced 2007 
Provided To Others? Yes  
Impact This has enabled us to perform many of HBV DNA assays at much lower cost compared to commercially available tests. The tool has been used to study the natural history of HBV chronic infection and for monitoring patients on ARV. 
 
Description LSHTM 
Organisation London School of Hygiene and Tropical Medicine (LSHTM)
Department Faculty of Epidemiology and Population Health
Country United Kingdom 
Sector Academic/University 
PI Contribution Conduct epidemiology study, and sero survey on HBV infection and vaccine efficcacy study in Keneba and Manduar
Collaborator Contribution The laboartory experiments for the host genetics studies were conducted by the collaboratorSupervision
Impact Generate DNA, now kept in archive Generate host genetic data from vaccinated individuals.
 
Description LSHTM 
Organisation London School of Hygiene and Tropical Medicine (LSHTM)
Department Faculty of Epidemiology and Population Health
Country United Kingdom 
Sector Academic/University 
PI Contribution Conduct epidemiology study, and sero survey on HBV infection and vaccine efficcacy study in Keneba and Manduar
Collaborator Contribution The laboartory experiments for the host genetics studies were conducted by the collaboratorSupervision
Impact Generate DNA, now kept in archive Generate host genetic data from vaccinated individuals.
 
Description degaule Foundation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Primary Audience Public/other audiences
Results and Impact Gave a talk to diners at a fund raising dinner

Improved awareness of the audience
Year(s) Of Engagement Activity 2008