Hepatitis B exposure - post exposure prophylaxis (PEP)

Hepatitis B is a serious viral infection that causes inflammation of the liver.

Infection with hepatitis B occurs through exposure to blood or secretions of someone with hepatitis B (acute or chronic). This usually occurs from mother to child during and after birth, but can also occur though unsafe sex, sharing drug injecting equipment, needle stick injury or unsafe tattoos.

What is hepatitis B post-exposure prophylaxis?

After possible exposure to the hepatitis B virus, hepatitis B post-exposure prophylaxis (PEP) can be used to decrease the chance of getting hepatitis B.

Hepatitis B PEP does not reduce the risk of infection with other blood borne viruses such as hepatitis C or HIV.

Hepatitis B PEP consists of:

What to do if you think you may need PEP

If you, or someone you know, may have been exposed to hepatitis B through unsafe sex, sharing drug injecting equipment, needle stick injury or other exposure, hepatitis B PEP may prevent hepatitis B.

Hepatitis B PEP must be given within 72 hours, though it is most effective if given as early as possible.

Hepatitis B PEP is available from hospital emergency departments, although you may be able to get it through your workplace if your exposure was at work.

The health care worker will assess for the risk of exposure. The health care worker will want to determine some facts about the source of your exposure:

  • Is the person known to be infected with hepatitis B?
  • Is the person in a high risk group for infection with hepatitis B?
  • Can the person be contacted?
  • Will the person consent to testing?

At the first visit blood tests may be done to check whether you have any sign of previous infection with hepatitis B, or immunity to hepatitis B virus. If the first blood tests show you are already immune to hepatitis B (usually due to vaccination) then no hepatitis B PEP is necessary.

After receiving the first injections for hepatitis B PEP you will need to return for two further injections at one month and six months.  Tests for hepatitis B infection will be repeated at six weeks, three months and six months.

If hepatitis B PEP is provided in a public hospital emergency department, after the first attendance you will be referred back to your GP or other health care worker for counselling, follow-up and ongoing care.

Window period

After infection with hepatitis B, it may take some time for the infection to be detected in blood tests. This is called the window period, which can be up to 6 months. However, hepatitis B PEP is only likely to be effective if given within 72 hours.

Help and assistance

For more information about hepatitis B PEP, contact your local doctor or nearest emergency department. If your exposure occurred at work you may also be required to report to your occupational health and safety (OHS) officer.

Hepatitis B in pregnant women

In Australia, women who are pregnant are routinely tested for hepatitis B. If the mother has hepatitis B, her baby should be given hepatitis B PEP within 24 hours of birth.


Hepatitis B vaccination is recommended as part of the routine vaccinations for infants. Hepatitis B vaccination is also available free for people at higher risk of getting hepatitis B  and recommended for people at higher risk of severe disease.

Stocks of hepatitis B immunoglobulin

Stocks of hepatitis B immunoglobulin in Australia are limited however they are usually held at:

  • major metropolitan public and private hospitals (Royal Adelaide Hospital, The Queen Elizabeth Hospital, Lyell McEwen Hospital, Flinders Medical Centre, Women’s and Children’s Hospital, Noarlunga Hospital, Modbury Hospital, Ashford Hospital, Wakefield Hospital, St Andrews Hospital)
  • many country public hospitals (although stocks may be small so may be required to be ordered in from the SA Red Cross Blood Service, phone (08) 8223 6090)
  • If required a General practitioner can also obtain hepatitis B immunoglobulin from the SA Red Cross Blood Service, phone (08) 8223 6090 for a direct patient need.

More information