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Does the BCG vaccine for TB help with COVID-19 (coronavirus)?

Medically reviewed by Melisa Puckey, BPharm. Last updated on March 21, 2023.

Can a TB (tuberculosis) vaccine be used for Covid-19 (coronavirus)?

Official answer


It is hoped the BCG vaccine will increase the body’s immunity against COVID-19 which is caused by the coronavirus SARS-COV-2, so will help patients fight the infection.

Clinical trials are currently underway to find out if the BCG vaccine will help.

  • The BCG vaccine is being studied in clinical trials against COVID-19 (the illness caused by the coronavirus SARS-COV-2).
  • An earlier clinical trial which was done on patients who had a virus similar to SARS-CoV-2, showed that the BCG vaccine helped to decrease the levels of the virus in the patient.
  • It is hoped that these studies will show the BCG vaccine may decrease the amount of coronavirus in COVID-19 patients and reduce the number of cases and severity of COVID-19.
  • The clinical trial will be a multi-centre randomised controlled study.

What is the BCG Vaccine?

  • The bacillus Calmette-Guérin (BCG) vaccine was developed and first used in 1921 to protect against tuberculosis (TB) infection.
  • The BCG vaccine contains a live, but weakened strain of Mycobacterium bovis, which is closely related to the microbe that causes tuberculosis.
  • When it is used for TB prevention, the BCG vaccine improves the immune response specifically against tuberculosis bacteria.
  • Another way the BCG vaccine has been found to work is by increasing the trained immunity so the immune system is boosted against other bacteria and viruses. It is hoped that this immune boosting effect of the BCG vaccine will help patients with COVID-19.

What other health conditions is the BCG Vaccine being studied for?

  • Allergy. Studies in Australia are looking at whether the beneficial effects the BCG vaccine has on the immune system can reduce allergic diseases in eczema, food allergy, hay fever and asthma.
  • Type-1 diabetes. A clinical trial showed how the BCG vaccine stabilized blood sugar levels, without producing low blood sugar levels in type-1 diabetes, which is an autoimmune disease.
  • Cancer. Clinical trials are studying how effective the BCG vaccine is in treating melanoma. Carcinoma in situ (bladder cancer) is an approved indication for TICE® BCG

What happens next?

We need to wait for the trials to be completed to find out how well the BCG vaccine works to reduce the rates of COVID-19, and whether it reduces the severity of illness and speeds up patients recovery.

The studies will also be looking for any side effects or any unexpected issues that may reduce BCG usefulness in COVID-19 patients.

Bottom line

  • BCG vaccine is currently being trialled to reduce the frequency and severity of COVID-19.
  • It is hoped the BCG vaccine will increase the trained immunity so the immune system is boosted against coronavirus SARS-COV-2.
  • The BCG vaccine is an Approved Vaccine Product by the FDA for the prevention of tuberculosis in people who have not been previously infected with M. tuberculosis and who are at high risk of being infected with M. tuberculosis.

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