Hep B is a viral infection transmitted through blood and other body fluids and most commonly from an infected mother to her infant. It attacks the liver and can cause very serious acute and chronic conditions. The WHO says that in 2015 over 800,000 deaths were caused by Hep B worldwide, including liver cancer caused by the virus. Sex workers, men who have sex with men (MSM) and healthcare workers are particularly at risk among adults. However, less than 5% of infected adults actually end up chronically infected while up to 90% of infected children under 6 years old will experience chronic infection. So most adults seem able to fight off the infection but not children.
There is no cure for those chronically infected and treatment is aimed at managing symptoms and preventing the virus from replicating. This can mean being on medication for life.
Africa and South East Asia are mainly affected, where the carrier rate is 5-10 times higher than in Europe. 
In the UK, the number of people affected each year is a bit uncertain. Even official sources vary a lot. The records of notifiable infectious diseases show cases of acute hep b in recent years at less than 100 while the Public Health England’s annual Acute Hepatitis B report says they received 5090 reports of acute cases in 2015 but could only confirm 368 as being so. At the same time a Foundation for Liver Research publication refers to Department of Health figures of 1300 cases each year. So basically anywhere between a few dozen and over a thousand new cases a year, depending on who is right.
Crucially, how many of these are children?
Referring back to one of the annual reports by Public Health England, in 2014 when they recorded 488 cases of “probable acute hepatitis b, nine were in children under 15. Seeing that this is data from a hepatitis b specific surveillance programme, maybe we can give this some weight? Therefore the risk to a child in the UK is already very low before we even consider risk factors. There is always a risk, even if small. So of course parents who have no concern about vaccines will want to vaccinate. But as the readers of this book are likely to be questioning whether or not vaccinating is right for their child, this very low number is an important part of their risk analysis.
Like with all diseases there are risk factors and if these don’t apply to you or your child, the risk is reduced. If they do, they may be at much higher risk than the above figures suggest. For children (only) the main risk factors are: being born to an infected mother, living with someone who is chronically infected and travelling to parts of the world where the disease is prevalent.
In the UK Hep B vaccination is part of Infanrix Hexa, which is replacing Pediacel sometime during autumn 2017.
- World Health Organisation website May 2017
- Hepatitis B: out of the shadows, Foundation for Liver Research, The Institute of Hepatology, University College London