Why all babies need the hepatitis B vaccine

What is hepatitis B?

Hepatitis B is a viral infection that attacks the liver. It can cause liver cirrhosis and liver cancer. The virus causes the deaths of more than one million people per year worldwide and infects around one million more. In the World Health Organization (WHO) European and Eastern Mediterranean regions, around 26 million people currently live with hepatitis B.

While there is no cure for hepatitis B, it can be prevented through vaccination.

Because many people – including the majority of adults – experience no symptoms when they are infected, they often are unaware until the disease is advanced.

In fact, the WHO estimates that 87 per cent of people who have hepatitis B do not know they have it. This means they also are at greater risk of passing it on to others.

Why is hepatitis B dangerous for children?

Babies and children with hepatitis B infection are more likely to show acute symptoms. Acute hepatitis B symptoms can include jaundice, diarrhoea, loss of appetite, fever, tiredness, and dark urine, among other symptoms. In some cases, it can lead to liver failure.

When hepatitis B becomes chronic – lasting for six months or more – it can cause severe long-term harm, including liver cancer and other liver diseases. This is especially likely to happen when it is contracted in childhood.

For every 20 adults infected with hepatitis B, 1 will develop chronic hepatitis. But for every 20 babies infected in their first year of life, 18 will. And for every 20 children infected between the ages of one and four, between 5 and 10 will.

One in four children with chronic hepatitis B go on to die from either liver cancer or liver disease.

How is hepatitis B transmitted to children?

Hepatitis B is caused by a virus that is transmitted through blood and other bodily fluids. While hepatitis B can be transmitted through sexual contact or needle-sharing, it can be transmitted in other ways too – especially because the virus can survive outside of the body, including on surfaces, for up to seven days.

For children, one of the most common ways to contract hepatitis B is from an infected mother during birth. This is because the virus does not cross the placenta – meaning a foetus will not necessarily get it during pregnancy. But exposure to the mother's blood during labour puts a newborn at high risk. It is not thought to be passed through breastmilk, unless the mother has cracked or bleeding nipples.

However, even the babies of mothers who do not have hepatitis B can still be at risk. Like adults, children can contract hepatitis B through unhygienic medical practices, such as needles, blades or other types of medical equipment. Past hepatitis B outbreaks have been traced back to hospital, dentistry, and even acupuncture settings.

Children also have contracted hepatitis B in other ways, such as by being bitten or scratched by other children at daycare and by being infected during wrestling practice from an asymptomatic team member.

In fact, around 30 per cent of people with hepatitis B do not know how they were infected.

This is why vaccination early in infancy is so important – and usually recommended for all babies, not just those whose mothers test positive for hepatitis B.

What is the hepatitis B vaccination?

The first hepatitis B vaccine was approved in 1981. It is 98 per cent effective against infection.

The WHO recommends that the first dose be given to all newborns within 24 hours after birth. Two or three more doses are given about four weeks apart.

The most common side effects are soreness at the injection site, and an elevated temperature for one to two days. Decades of research have found no association between the hepatitis B vaccination and autism, multiple sclerosis or any other neurological or developmental disorder.

Before the vaccine was widely available, around 1 in 20 children worldwide had hepatitis B.

Now, less than 1 in 100 do.