Hepatitis B

Hepatitis B is a virus that infects the liver. It can be diagnosed by a blood test. There is a good vaccination available to prevent people getting hepatitis B and we recommend and provide it for people who are at risk of catching it sexually.

Hepatitis B is a virus that infects the liver. It is passed on easily through unprotected sex, particularly between men who have sex with men. Sharing injecting equipment for drug taking is another possible pathway for hepatitis B transmission. Hepatitis B is actually 100 times more infectious than HIV.

Most people (around 90-95%) who get hepatitis B are able to fight off the virus and are then unable to pass it on or catch it again (they become immune). However, it can become a chronic illness in some people, meaning that they have the illness in the long-term. This is very common in young children and babies.

People who have the chronic hepatitis B infection are called chronic carriers. Around two thirds of these people don’t get sick or die of the virus, but they can pass it on to other people.

The rest can go on to develop a disease of the liver, which can become very serious. Many will develop scarring of the liver (this is called cirrhosis). Chronic hepatitis B is also linked to an increased risk of developing liver cancer.


Hepatitis B is present in bodily fluids such as semen, vaginal fluid, saliva and blood.

It is transmitted through unprotected sex or sharing needles for injecting drugs. Infected mothers can also transmit hepatitis B to their babies during pregnancy, childbirth or breastfeeding. For this reason, all pregnant women in the UK are tested for hepatitis B.

You are at particular risk of catching hepatitis B if:

  • You have unprotected sex with various partners.
  • You work closely with blood and/or other bodily fluids.
  • You use needles for tattooing, piercing or acupuncture that have not been sterilised.
  • You share equipment for drug taking, including spoons, filters and needles.
  • You have “rough” sex that causes tears in the skin.

There is also a small risk of catching hepatitis B from sharing towels, razors and toothbrushes that might be contaminated with blood.


Many people who are infected with hepatitis B don’t even realise it because they might have no symptoms for many years.

Sometimes people who have hepatitis B have symptoms after the initial infection. Symptoms to look out for are feeling sick and vomiting, loss of appetite, itchy skin, jaundice (yellow skin and whites of eyes, and dark urine), diarrhoea or a mild flu-like illness.


A blood test is used to diagnose hepatitis B. You can get this at your sexual health clinic.


You will be referred to your GP for further assessment if you have acute or chronic hepatitis B.

A liver specialist will prescribe treatment for chronic hepatitis B.


We recommend and provide a vaccination for people who are particularly at risk of catching hepatitis B sexually. This includes all sex workers, men who have sex with men and those with a high risk partner. You can also prevent hepatitis B transmission by using condoms for sex and clean needles and works if you’re injecting drugs.


This guide to Hepatitis B for men who have sex with men will provide you with information about Hepatitis B – its symptoms, treatments and prevention.

You can listen to our audio resource on Hepatitis B here.


Can I drink alcohol after the injection?

Yes. The vaccine does not interact with alcohol.


Can I have sex after the injection?

Yes, the vaccine does not contain real Hepatitis B virus. You cannot pass it on.


Does the vaccine affect drugs/medicines?

No, the vaccine does not interact with prescribed or recreational drugs.


What if I'm late with one of the injections?

It is important to complete all 3 injections. Generally the advice is that if you are more than six months late with your second injection or more than one year late for your third injection you will need to start the course of injections back at the beginning.


When will I become protected?

The only way to be sure you have become protected is to have a blood test several weeks after the last injection. The table below shows the percentage of people who become protected at each stage.

After one injection 41%
After two injections 86%
After three injections 97%


Does the vaccine protect me for life?

Booster doses are recommended every 5 years. The antibodies that protect you from the Hepatitis B virus will slowly fall over time in your blood. The booster is recommended to keep your antibody levels high and protect you from infection.


What is in the vaccine?

The vaccine does not contain real Hepatitis B virus.


What are the side effects?

Side effects are uncommon. The most common is some mild soreness or redness at the site of the injection. Other possible side effects include fever, rash, muscle and joint aches. Severe allergic reactions (anaphylaxis) are extremely rare and are treated with an injection of adrenaline.


Is there anyone who can't have the vaccine?

It is recommended that people unwell with high fevers (e.g. flu) should wait until the illness has settled. Anyone who has had a severe allergic reaction to a Hepatitis B vaccine should not have further doses. (Severe allergic reactions are extremely rare).


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