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BCG vaccine

Generic name: BCG vaccine [ BCG-VAX-een ]
Dosage form: percutaneous powder for injection (50 mg)
Drug class: Bacterial vaccines

Medically reviewed by on Nov 28, 2023. Written by Cerner Multum.

What is BCG vaccine?

BCG vaccine is used to help prevent tuberculosis (TB) in adults and children who have never had this disease and test negative for tuberculosis. BCG vaccine is recommended if you live with or have close contact with someone who is infected with tuberculosis.

This vaccine helps your body develop immunity to the TB, but will not treat an active infection you already have.

Like any vaccine, the BCG vaccine may not provide protection from disease in every person.

BCG vaccine may also be used for purposes not listed in this medication guide.

BCG vaccine side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

BCG vaccine may cause serious side effects. Call your doctor at once if you have:

Some side effects may occur up to 5 months after you receive BCG vaccine. These side effects may also last for several weeks.

Common side effects of BCG vaccine may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


You should not receive this vaccine if you have a weak immune system caused by disease such as HIV or cancer, or by using steroids or receiving chemotherapy or radiation.

Before taking this medicine

You should not receive BCG vaccine if you are allergic to it, or if you have a weak immune system caused by:

Tell your doctor if you have ever had:

It is not known whether BCG vaccine will harm an unborn baby. However, this vaccine is not recommended for pregnant women.

Do not breastfeed.

How is BCG vaccine given?

Before you receive BCG vaccine, your doctor will perform a skin test to make sure you do not have tuberculosis.

BCG vaccine is not given with a needle and syringe, as most other vaccines are. Instead, the BCG vaccine is a liquid placed directly onto the skin of your upper arm. Then a multi-pronged needle device is used to prick the skin through the liquid to deliver the vaccine into the shallow layers of skin. These needle sticks are not deep, but they will cause some soreness and minor bleeding.

You may have flu-like symptoms for up to 2 days after you receive BCG vaccine. Call your doctor at once if you have a fever of 103 degrees F or higher.

Within 10 to 14 days after receiving this vaccine, you should see small red bumps on your skin where the vaccine and needle device were placed. This red area will gradually grow larger after 4 to 6 weeks, and then scale and fade. After 6 months you will most likely have little to no scar.

BCG vaccine contains a live form of tuberculosis bacteria, which can "shed" from your injection site. This means that for a short time after you receive the vaccine, your vaccination sore will be contagious and could spread the bacteria to anything or anyone who touches it.

Keep your vaccination sore loosely covered with clothing or a light gauze dressing for at least 24 hours.

Tell your doctor if you have any unexpected skin changes or severe irritation, lesions, or oozing where the needle sticks were placed. These reactions could occur up to 5 months after you received BCG vaccine.

You will need another TB skin test 2 to 3 months after you received the BCG vaccine.

What happens if I miss a dose?

This vaccine is usually given as a single dose. You may need a repeat vaccine if your TB skin test is still negative 2 to 3 months after you received your first BCG vaccine.

What happens if I overdose?

Since this vaccine is given by a healthcare professional, an overdose is unlikely to occur.

What should I avoid after receiving BCG vaccine?

Avoid touching your vaccination sore for at least 24 hours.

What other drugs will affect BCG vaccine?

Before receiving this vaccine, tell the doctor about all other vaccines you have received in the past 30 days.

Tell your doctor about all medicines you use, especially:

This list is not complete. Other drugs may affect BCG vaccine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Frequently asked questions

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.