Hepatitis B is highly contagious. You can be infected if you come into contact with blood or other body fluids from someone who carries the virus, even if that person shows no signs of illness. The greatest risk of infection occurs at birth when a mother who carries the virus can pass it on to her baby¹.

Infection can also occur:

• during breastfeeding, if the mother carries the virus
• when adults or children come into contact with the open sores or cuts of an infected adult or child
• when adults or children share certain personal items with an infected person, such as a tooth brush
• when adults or children eat or share food that has been chewed or sucked by an infected person
• when adults or children are bitten by an infected person
• as a result of sharing needles or a needle stick injury
• when someone has unprotected sex with an infected person.

The virus can survive on objects for up to seven days, so infection can occur a number of days after an adult or child has been in contact with someone who carries the virus.

The hepatitis B virus is highly infectious and is 50 to 100 times more infectious than HIV, the human immunodeficiency virus that causes AIDS³.

The risks associated with hepatitis B are much greater for babies than they are for adults. Around 90 per cent of babies who catch hepatitis B at birth develop chronic hepatitis B. (Less than 10 per cent of adults who get the infection develop chronic hepatitis B².)

• There is no cure for chronic hepatitis B infection.
• People with chronic hepatitis B need long-term antiviral therapy to reduce the risk of developing liver cancer⁴.

Around one in four babies who catch hepatitis B at birth or soon after will die of liver failure or liver cancer as an adult⁵.

Most adults who are infected with the hepatitis B virus recover fully. While infected, they may have no symptoms at all or very mild flu-like symptoms, or they may suffer from fever, nausea and vomiting, pain in the liver, pain in the joints and yellowing of the skin (called ‘jaundice’). Around 10 per cent of adults with a hepatitis B infection develop chronic hepatitis B which can lead to liver disease and liver cancer².

In 2013 there were around 210,000 people living with chronic hepatitis B, and around 389 deaths related to chronic hepatitis B⁶. Overall, hepatitis B is not as common in Australia as it is in some other countries, however it is more common within some groups including Aboriginal and Torres Strait Islander communities.

The vaccine works by training your baby’s immune system to recognise and get rid of the hepatitis B virus. The vaccine contains ‘antigens’ which are tiny fragments of the hepatitis B virus. When your baby’s immune system detects the antigens in the vaccine, it produces antibodies to fight them and get rid of them.

Hepatitis B is a viral infection and the antigen in the hepatitis B vaccine is a tiny, synthetically made fragment of the virus. The vaccine does not contain any blood products and is not a ‘live’ vaccine. The synthetic fragments cannot reproduce themselves or cause disease.

Between 90 and 95 per cent of people under 40 who have had three doses of the hepatitis B vaccine, as recommended in the National Immunisation Program, are protected against the hepatitis B virus⁷.

Some lifestyle factors - including age, obesity, certain infectious diseases or a history of smoking - can impact on the effectiveness of the hepatitis B vaccine. Speak with your doctor if you have questions about how lifestyle factors could impact on the effectiveness of the vaccination for your baby, or anyone else in your family.

Premature babies are even more vulnerable to infection than full-term babies. For that reason, it is just as important to give the hepatitis B vaccine to premature babies to protect them from this serious infection. Your doctor or nurse can advise you on the best time for your baby to have their first dose of the vaccine, and whether an additional dose is required.