Around 600,000 people die each year from the acute or chronic consequences of hepatitis B, with 25% of adults who are chronically infected during childhood later dying from liver cancer or cirrhosis.
Researchers from the School have been leading studies into the effectiveness of a hepatitis B vaccine in The Gambia - one of the countries worst affected by the virus.
Since 1986 the Gambia Hepatitis Intervention Study, a collaboration between the School, the World Health Organization (WHO) cancer agency and the Medical Research Council (MRC) The Gambia Unit, has been evaluating the effectiveness of administering a hepatitis B vaccine to infants.
Sir Andrew Hall, emeritus professor of epidemiology, has been the lead investigator on the project since its inception and has published many papers analysing the efficacy of the vaccination as the trial cohort ages.
Around 126,000 children were recruited to the study in the first phase, with half receiving the vaccine. In phase two of the study the vaccine was evaluated and phase three continues to follow up the children into adulthood. Phase two demonstrated that the vaccine was 84% effective against infection and 94% effective against chronic carriage. Hall has also shown that the vaccine is cost effective and is a model that can be replicated in other African countries.
A 1999 paper demonstrating vaccine efficacy at the age of nine persuaded WHO to recommend the introduction of a hepatitis B vaccine into the routine vaccination schedule across Africa. Babies should receive three doses of the vaccine, with WHO also recommending that the vaccine should be administered within 24 hours of birth, based on the study’s findings.
Research in 2007 showed that vaccination in early life gives long-lasting protection, despite a reduction in antibody levels. And further studies showing good levels of protection in 18 and 22 year olds have led WHO to state explicitly that there is no need for an expensive booster programme. A booster would have had serious cost implications for cash-strapped ministries of health in developing countries and Hall’s evidence was crucial in the development of this policy.
As of 2008 177 countries have included the hepatitis B vaccine in their routine schedule. The recent decision by Liberia, Niger, Central African Republic, Chad and Namibia to include the vaccine means there is now almost universal coverage in Africa, with an extra 1.2 million children a year protected from contracting potentially fatal liver disease later in life.
Hall received a knighthood for services to public health in 2013 with his citation noting his seminal contribution to hepatitis B vaccination.