Family doctor

Overview:

• The hepatitis B vaccine protects against hepatitis B
• The hep B vaccine is prepared synthetically
• The vaccine is 90 percent effective in young children
• It is the first vaccine that can protect against cancer (liver cancer)
• The vaccine is safe, though some people may feel unwell and have diarrhoea
• The vaccine is routinely given at six weeks, three months and five months

What is it?

The hepatitis B vaccine is a synthetically made yeast derived vaccine. The body is stimulated by the vaccine to form antibodies against the actual hepatitis B virus.

There are two different types of the vaccine in New Zealand. One is called Engerix-B and the other is called HB-II Vax. There is a new vaccine which also protects against Hepatitis A (Twinrix) but this is not part of the free childhood immunisation schedule.

The vaccine is 90 percent effective in children but is less effective in those over 30.

For further more detailed information about hepatitis B, please refer to the detailed article on the illness.(keyword=hepatitis B)

In summary;

• Hepatitis B can cause liver cancer in some people.
• Most people recover from hepatitis B but some people can become chronic carriers and the virus can stay in the liver and lead to liver damage and cancer. Chronic carriers can pass the virus on to others through infected blood or sexual intercourse.
• Cancer of the liver occurs in about five to 15 percent of chronic carriers. The risk of becoming a chronic carrier is highest in infants. About 90 percent of infected babies become chronic carriers.
• The Hepatitis B vaccine is the first vaccine that can protect against cancer (liver cancer, which is very common worldwide).

Below is a summary of a World Health Organization (WHO)expert committee press release on Hepatitis B:

• Over 1 billion doses of Hepatitis B vaccine have been used since 1981 with an outstanding record of safety and efficacy.
• Hepatitis B is the first vaccine against a human cancer.
• Recognising the enormous value of Hepatitis B vaccine, the World Health Assembly recommended in 1992 that all countries incorporate Hepatitis B vaccine into their national immunisation programmes. To date 100 countries have done so.
• WHO strongly recommends that all countries already using Hepatitis B vaccine as a routine vaccine continue to do so, and that countries not yet using the vaccine begin as soon as possible.  

What are the side effects?

The hepatitis B vaccine is a safe vaccine. Some people get redness and pain at the injection site, and some may feel unwell or have diarrhoea for a short time.

The media raised concerns that the hepatitis B vaccine could lead to serious diseases such as multiple sclerosis and other autoimmune disorders. However, there is no strong medical evidence to support this link.

However, France recently stopped vaccinating teenagers against hepatitis B as a result of public pressure. They still immunise babies and at-risk adults.

When should the vaccine be given?

The vaccine is given at six weeks, three months and five months.

All pregnant women are offered a blood test to see if they are carrying the hep B virus. If they are, their babies are at high risk of becoming chronic carriers.

Babies born to infectious mothers are given a double dose of the hepatitis B vaccine soon after they are born. They are also given an injection of antibodies to the hep B virus to help them fight off the virus. They are also given a double dose of the vaccine at six weeks and three months, and a normal dose at five months.

Other people who should be immunised include adults who work in hospitals and come into contact with blood, those who work in handicapped institutions, homosexual and bisexual men, heterosexuals with more than one partner, injecting drug users, haemodialysis patients, and contacts of people who are chronic carriers of the virus.

Where to get more information:

Your doctor, practice nurse or plunket nurse will be able to help.

The Immunisation Advisory Centre, Auckland. Ph 0800 IMMUNE (0800 466 863).

 *This information was provided by the New Zealand Immunisation Advisory Centre.