Tuberculosis (TB) is a disease caused by the bacteria called Mycobacterium tuberculosis. It is spread via droplets through coughing and sneezing. It primarily affects the lungs, however it can spread to the lymph nodes, the brain, kidneys, or spine. Common symptoms of pulmonary TB include fever, cough, chest pain and night sweats.

TB infection can be categorised as having active disease (displaying symptoms and being infectious) or latent TB infection (the bacteria is dormant, there are no symptoms, and the patient is not infectious). Latent TB can become active if an infected person’s immune system becomes weakened.

Australia has one of the lowest rates of TB disease in the world, but it remains very common in some countries, including places Australians frequently travel to visit friends and relatives (VFR).

About BCG vaccine

The BCG vaccine is a live-attenuated vaccine. It was developed from a bacteria similar to TB called Mycobacterium bovis and is weakened so that it will not cause disease in healthy humans.

The BCG vaccine does not prevent someone being infected with the bacteria that causes TB, but it can prevent the development of serious disease. It is specifically designed to prevent TB in children and can be given from birth onwards.  The World Health Organization (WHO) currently recommends a single lifetime dose.

How to administer BCG

The BCG is given intradermally as a single dose of vaccine and can only be administered by a medical or nursing professional who is trained in BCG vaccination working within a recognised BCG clinic [see resources].

The recommended site of vaccination is on the left arm over where the deltoid muscle inserts into the humerus. Administration at this site will minimise the risk of keloid scarring.

If active eczema, dermatitis or psoriasis is present at the site of injection, vaccination should be deferred until the skin can be treated and is clear of symptoms.

Who should be immunised?

In Australia, the BCG vaccine is recommended for specific groups:

When travelling to endemic countries BCG should be administered at least 4-6 weeks prior to departure, to ensure vaccine effectiveness prior to exposure.

Tuberculin skin testing (TST/Mantoux)

Tuberculin skin testing (TST) or Mantoux testing, involves the intradermal injection of a tuberculin purified protein derivative (PPD). Everyone ≥ 6 months of age should have a TST performed prior to BCG vaccination to identify if a person already has a level of immunity to TB. In people who have previously received a BCG or have previously had TB exposure, a hypersensitivity reaction can be recognised 48-72 hours later.

It is important to note that TST results may be unreliable for 4-6 weeks following a measles infection or receiving a measles-containing vaccine.

What to expect following BCG vaccine

BCG, like all vaccines, has a list of common and expected side effects and a list of rare side effects that may occur in the weeks following [refer to What to expect following the BCG vaccination- RCH parent handout for more information].

Common/expected reactions:

  1. a small red papule will appear at the injection site in the weeks following the vaccine
  2. an ulcer (open sore) may develop 2-3 weeks later (usually less than 1 cm in diameter) and last from a few weeks to months
  3. the majority of infants will develop a flat scar at the site once the ulcer heals.

Rare of more serious side effects:

  1. axillary lymphadenopathy (swelling of the lymph nodes under the left arm)
  2. persisting ulcer lasting longer than a few months
  3. a large abscess (collection of pus) at the injection site
  4. keloid scarring at the site.

If you suspect a rare or serious side effect, it is strongly recommended to seek medical advice either from a GP or the medical clinic where the BCG was administered.

For specialist immunisation advice or to report an adverse event following immunisation (AEFI), please contact SAEFVIC.

Refer to the useful resources and links below to find out more about the BCG vaccine.


BCG Clinics in Victoria

Useful links

Authors: Nigel Crawford (Director SAEFVIC, Murdoch Children’s Research Institute) and Rachael McGuire (SAEFVIC Research Nurse, Murdoch Children’s Research Institute)

Reviewed by: Mel Addison (SAEFVIC Research Nurse, Murdoch Children’s Research Institute), Rachael McGuire (SAEFVIC Research Nurse, Murdoch Children’s Research Institute) and Francesca Machingaifa (SAEFVIC Research Nurse, Murdoch Children’s Research Institute)

Date: July 15, 2022

Materials in this section are updated as new information and vaccines become available. The Melbourne Vaccine Education Centre (MVEC) staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family’s personal health. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult a healthcare professional.