Tuberculosis: Global Burden, the BCG Vaccine and New Vaccines

Last updated November 1, 2026

Tuberculosis (TB) is an infectious disease caused by bacteria. It most often affects the lungs, and it spreads through the air when people with TB cough, sneeze or spit.

TB is preventable and curable. Even so, the World Health Organization (WHO) says TB is the world’s leading cause of death from a single infectious agent. A vaccine called BCG protects young children from severe TB, but it does not protect everyone, and researchers are now testing new vaccines.

How Big Is the Problem?

WHO’s latest figures show the size of the TB burden:

  • In 2024, an estimated 10.7 million people fell ill with TB. This included 5.8 million men, 3.7 million women and 1.2 million children.
  • In 2024, 1.23 million people died from TB, including 150,000 people with HIV.
  • About a quarter of the world’s population is estimated to have been infected with TB bacteria.
  • Global efforts against TB have saved an estimated 83 million lives since 2000.

TB is found in all countries and age groups. Over 80% of cases and deaths are in low- and middle-income countries. In 2024, the largest numbers of new cases were in the WHO South-East Asia Region (34%), the Western Pacific Region (27%) and the African Region (25%).

Eight countries had two-thirds of all cases: India (25%), Indonesia (10%), the Philippines (6.8%), China (6.5%), Pakistan (6.3%), Nigeria (4.8%), the Democratic Republic of the Congo (3.9%) and Bangladesh (3.6%).

TB Infection and TB Disease

Most people who are infected with TB bacteria do not feel sick and cannot spread the bacteria. This is called TB infection. About 5 to 10% of people with TB infection will later get symptoms and develop TB disease. Babies and children who are infected have a higher risk of developing the disease.

Some conditions raise the risk of TB disease:

  • Diabetes.
  • A weak immune system, for example from HIV.
  • Undernutrition.
  • Tobacco use.
  • Harmful use of alcohol.

People living with HIV are 12 times more likely to fall ill with TB disease than people without HIV. TB is the leading cause of death among people with HIV.

Symptoms of TB

TB symptoms may be mild for many months. This makes it easy to spread TB to others without knowing it. Some people with TB disease have no symptoms but can still spread it.

Common symptoms include:

  • A long-lasting cough, sometimes with blood.
  • Chest pain.
  • Weakness and tiredness.
  • Weight loss.
  • Fever.
  • Night sweats.

TB usually affects the lungs, but it can also affect the kidneys, brain, spine and skin.

See a healthcare provider if you have a long-lasting cough, fever or weight loss that you cannot explain. Early treatment helps stop the spread of TB and improves the chance of recovery.

Diagnosis and Treatment

WHO recommends rapid tests as the first tests for anyone with signs and symptoms of TB. These tests can give first results within 48 hours of sample collection. Skin tests and blood tests can find TB infection. The results help show which people at high risk will benefit most from preventive treatment.

TB disease is treated with special antibiotics. The most common are rifampicin, isoniazid, pyrazinamide and ethambutol. The medicines must be taken every day for 4 to 6 months. Stopping early, or without medical advice, is dangerous, because the bacteria can become resistant to the drugs.

Multidrug-resistant TB (MDR-TB) does not respond to rifampicin and isoniazid, the 2 most effective first-line drugs. MDR-TB can be treated and cured with other drugs, but only about 2 in 5 people with drug-resistant TB got treatment in 2024.

TB preventive treatment stops TB infection from becoming TB disease.

The BCG Vaccine

BCG (Bacille Calmette-Guérin) is the vaccine used against TB. In countries where TB is common, it is given to babies and small children.

BCG prevents deaths from TB. It protects children from serious forms of TB, such as TB meningitis and miliary TB.

The Limits of BCG

BCG has important limits:

  • It gives only partial protection to babies and young children.
  • It does not protect teenagers and adults, who cause most TB transmission.
  • Its effect against TB of the lungs in adults varies.
  • It can cause a false-positive TB skin test. A TB blood test is the preferred test for people who have had BCG.

People who are immunosuppressed, such as people with HIV, should not receive BCG. Pregnant women should not receive it either.

Because of the low risk of TB infection and the limits of the vaccine, BCG is not generally used in the United States. It is considered only for people who meet specific criteria, in consultation with a TB expert.

New TB Vaccines in Trials

WHO calls new TB vaccines a priority and an important unmet medical need. It wants vaccines that protect adults against TB of the lungs, and vaccines for babies that are safer and work better than BCG.

As of August 2025, 18 TB vaccine candidates were in clinical development, up from 15 in 2024:

  • 4 were in Phase I trials.
  • 8 were in Phase II trials.
  • 6 were in Phase III trials.

The candidates use different types of technology, including messenger RNA (mRNA), viral vectors, proteins with adjuvants, and inactivated or live weakened mycobacteria. Some aim to prevent TB infection or disease. Others aim to improve treatment results for people with active TB. WHO notes that only a minority of early candidates are expected to reach licensure.

M72/AS01E

One candidate, M72/AS01E, has shown promising results. In a Phase IIb trial in Kenya, South Africa and Zambia, it was given to people with signs of TB infection. Over about 3 years, it showed an estimated efficacy of 50% against TB disease (90% confidence interval, 12 to 71%). WHO described the result as an important scientific breakthrough.

A Phase 3 trial is now testing the vaccine’s safety and efficacy. The trial reached full enrollment 11 months ahead of schedule, with about 20,000 participants at 54 sites in 5 countries. Its partners include the Gates Foundation, GSK and the Wellcome Trust. If it is proven well tolerated and efficacious, M72/AS01E could be the first new TB vaccine in 100 years.

In 2023, WHO’s Director-General set up a TB Vaccine Accelerator Council to help develop, test, authorize and use new TB vaccines.

Prevention Today

WHO advises these steps to help prevent TB infection and spread:

  • Get screened for TB if you are at higher risk, such as if you have HIV or live or work with people who have TB.
  • If you are prescribed TB preventive treatment, complete the full course.
  • If you have TB, cover your mouth and nose when you cough or sneeze, wear a mask and avoid contact with other people.

TB is closely linked to HIV. To learn about research in that field, read about the search for an HIV vaccine. To learn more about other vaccine-preventable diseases, read our disease information or learn about the World Health Organization.

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