Vaccine effectiveness of routine infant hepatitis B vaccination/hepatitis B vaccine impact under immunisation programme
Lead Research Organisation:
MRC Unit, The Gambia
Abstract
We will check how well the hepatitis B vaccine is working by taking small blood samples from 7,700 people aged from 1 to 21 across the country. By comparing vaccinated people against unvaccinated we will see if the protection against infections with hepatitis B that was seen in earlier studies continues into adulthood. We need to do this as liver disease (especially liver cancer) caused by Hepatitis B is a major killer in The Gambia and as the vaccine was only introduced 21 years ago we do not yet know if the vaccinations given in childhood are going to prevent infections and disease in adults.
Technical Summary
We propose to study the effectiveness of Hepatitis B (HBV) vaccination in infancy against chronic active hepatitis in early adulthood. This will provide new evidence to determine if there is continued protection against HBV carriage and disease after such a long period of time and whether it continues despite the onset of sexual activity. Additionally we will screen those born since the introduction of HBV vaccination into the Expanded Programme of Immunisation (EPI) to further measure the impact of routine vaccination, specifically: what level of carriage is present at different ages; how these appear to be acquired; if rates follow a trend over time; and if there has been a shift in the viral genotype. Approximately 3,200 17-21 year olds from the Gambia Hepatitis Intervention Study (GHIS) will have blood samples taken and 4,500 under 17s who were born since the end of the GHIS will be screened for HBV. This information will inform decisions on the value of a booster dose of vaccine in teenagers, whether there is perinatal transmission that can be averted by giving a first dose of the vaccine on the day of birth, and will describe the performance of the EPI in real life conditions. The existing GHIS, and the following early adoption of the HBV vaccine nationwide, makes this a unique population in which to answer these questions and further define the effectiveness of the HBV vaccine. The large number of blood samples collected will also allow for the genetic testing of host and viruses.
People |
ORCID iD |
Tom Peto (Principal Investigator) |
Publications

Description | demonstration of long-term hepatitis B vaccine efficacy in Africa |
Geographic Reach | Africa |
Policy Influence Type | Citation in other policy documents |
Title | Hepatitis B vaccine efficacy survey 2007/8 sera samples and DNA samples stored in Fajara, The Gambia |
Description | Under Dr Maimuna Mendy we have approximately 2,700 thousand sera samples and DNA samples from a cross-sectional study that are retained for future use by the Viral Diseases Programme. |
Type Of Material | Database/Collection of Data/Biological Samples |
Provided To Others? | No |
Impact | results from these samples are still being analysed. |
Description | Community awareness meetings for hepatitis B surveys in The Gambia |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | Local |
Primary Audience | Participants in your research and patient groups |
Results and Impact | We held meetings to explain the study we were conducting We had a good response. |
Year(s) Of Engagement Activity | 2007,2008 |
Description | Joint International Tropical Medicine Meeting |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Paper Presentation |
Geographic Reach | National |
Primary Audience | Health professionals |
Results and Impact | Presenting work from hepatitis B surveys in The Gambia at a medical conference none |
Year(s) Of Engagement Activity | 2012 |
Description | Open day at the Medical Research Council Laboratories, The Gambia |
Form Of Engagement Activity | Participation in an open day or visit at my research institution |
Part Of Official Scheme? | No |
Type Of Presentation | Workshop Facilitator |
Geographic Reach | Local |
Primary Audience | Schools |
Results and Impact | We held a stall to explain hepatitis B to secondary school children. We had good response from the children who attended. |
Year(s) Of Engagement Activity | 2007 |
Description | Presentation at the Clinical Trials Service Unit, University of Oxford |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | National |
Primary Audience | Health professionals |
Results and Impact | presenting work from my PhD on hepatitis B in The Gambia none |
Year(s) Of Engagement Activity | 2012 |
Description | Presentation of data from Gambian HBV surveys to JCVI |
Form Of Engagement Activity | A formal working group, expert panel or dialogue |
Part Of Official Scheme? | Yes |
Type Of Presentation | Paper Presentation |
Geographic Reach | National |
Primary Audience | Policymakers/politicians |
Results and Impact | Unpublished data from the 2007-08 GHIS survey was presented alongside all other HBV efficacy studies as part of a review. Not yet known, data should confirm the long-term vaccine efficacy of infant HBV immunization in Africa. |
Year(s) Of Engagement Activity | 2012 |
Description | Radio presentation in the Gambia |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Type Of Presentation | Keynote/Invited Speaker |
Geographic Reach | Local |
Primary Audience | Public/other audiences |
Results and Impact | We presented a call-in show on Radio Basse to educate people about hepatitis B and inform communities of a study that we were conducting We had people phone in with questions and we reached a wide audience |
Year(s) Of Engagement Activity | 2008 |
Description | visit to Ministry of Health in The Gambia |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Primary Audience | Health professionals |
Results and Impact | Discussions with MoH Immunisation team in The Gambia We are continuing to work in partnership with the health authorities in The Gambia as part of a long term collaboration "The Gambia Hepatitis Intervention Study". |
Year(s) Of Engagement Activity | 2009 |